JPH0669443B2 - Medical conductive adhesive and medical adhesive electrode using the same - Google Patents

Description

The present invention relates to a medical conductive adhesive having excellent conductivity and adhesiveness, and a medical adhesive having a layer of the adhesive provided on the surface of an electrode plate. Regarding electrodes.

(Prior art) When using medical electrical equipment such as an electrocardiograph, electromyography, electroencephalograph, low-frequency therapy device, and surgical scalpel, attach a signal electrode or ground electrode to the skin surface. However, a predetermined place on the skin surface is electrically connected to these devices, or the skin surface is grounded. Various improvements have been made on the material and shape of the medical electrode and the means for fixing the electrode to the skin surface. For example:

(1) Conductive paste, cream containing electrolyte,
A method of attaching a metal electrode plate to the skin surface with a conductive medium such as an aqueous gel.

(2) A method in which a sponge surface of a medical electrode in which a sponge containing a conductive liquid or a gel-like substance, an electrode plate and an adhesive sheet for sticking is integrated is pressed against the skin surface and fixed with the sheet. And (3) A method of using an adhesive electrode in which a layer of an electrically conductive adhesive is provided on the surface of an electrode plate.

Of these methods, the method (3) of using an adhesive electrode is simple and suitable because the change in conductivity is small even when the electrode is attached to the skin surface for a long time, and the electrode is manufactured at a relatively low cost. is there. As an adhesive that can be used for such an adhesive electrode, for example, the following conductive adhesive has been proposed.

The adhesive for electrodes disclosed in JP-A-52-95895 is
It contains a polymer containing an ester of an α, β-olefinically unsaturated carboxylic acid and a monohydric or polyhydric alcohol having a quaternary ammonium group at the terminal, and a polyhydric alcohol.

The adhesive for electrodes disclosed in JP-A-56-36939 is
It contains a polymer containing a salt of an organic carboxylic acid such as (meth) acrylic acid or maleic acid (alkali metal salt, amine salt, etc.) in a proportion of 5 mol% or more and a polyhydric alcohol such as glycerin.

The adhesive for electrodes disclosed in JP-A-56-36940 is
It contains a nonionic hydrophilic polymer such as polyacrylic acid or polyvinyl alcohol and a water-soluble plasticizer such as glycerin.

However, it cannot be said that the adhesives of the above three examples have sufficient conductivity. In particular, the adhesive of (1) itself has extremely low conductivity, and it is necessary to mix an electrolyte such as sodium chloride. In terms of adhesiveness, none of them are sufficient, and the electrode cannot be adhered to the skin surface for a long time. Generally, when the adhesiveness of the adhesive is set to be high, the conductivity is lowered, and when the conductivity is set to be high, the adhesiveness tends to be lowered.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is that it can be used in various medical measuring instruments and the like and has excellent conductivity and adhesiveness. To provide a conductive adhesive having Another object of the present invention is to provide a medical adhesive electrode in which an adhesive layer having the above-mentioned excellent properties is provided on the surface of an electrode plate.

(Means for Solving the Problems) The conductive pressure-sensitive adhesive of the present invention contains a polymer having a substituted and substituted ammonio group, water, and magnesium chloride, whereby the above object is achieved.

The conductive pressure-sensitive adhesive of the present invention contains a polymer having a substituted ammonio group; water; magnesium chloride; and a corrosion inhibitor composed of hydroquinone and / or a hydroquinone derivative; thus, the above object is achieved.

In the medical adhesive electrode of the present invention, the conductive adhesive layer is provided on at least a part of the electrode plate, and the adhesive contains a polymer having a substituted ammonio group, water and magnesium chloride, whereby the above-mentioned object is achieved. Is achieved.

The polymer, which is the main component of the medical conductive adhesive of the present invention, comprises a copolymerization component (first) of a (meth) acrylamide derivative (I) and / or a (meth) acrylic acid ester derivative (II) having the following structural formula. It is a copolymer contained as one copolymerization component).

(Wherein R ₁ is H or CH ₃ ; R ₂ is a saturated hydrocarbon group having 1 to 6 carbon atoms; R ₃ , R ₄ and R ₅ are alkyl groups having 1 to 4 carbon atoms;
And X is a halogen atom such as Cl or Br) (Here, R ₆ is H or CH ₃ ; R ₇ is a saturated hydrocarbon group having 1 to 6 carbon atoms or a saturated hydrocarbon group having 1 to 6 carbon atoms and having a hydroxyl group; R ₈ , R ₉ and R ₁₀ are An alkyl group having 1 to 4 carbon atoms; and X is a halogen atom such as Cl or Br).

Among the compounds represented by the above structural formulas, the (meth) acrylamide derivative (I) includes 2 (acrylamido) ethyltrimethylammonium chloride, 2 (methacrylamido) ethyltrimethylammonium chloride, 3 (acrylamido) propyltrimethylammonium chloride, 3 (acrylamido) propyltrimethylammonium chloride, Examples include (methacrylamido) propyltrimethylammonium chloride, 3 (methacrylamido) propyldiethylmethylammonium chloride, 3 (methacrylamido) propyltrimethylammonium bromide, and 3 (acrylamido) isopentyltrimethylammonium chloride. Examples of the (meth) acrylic acid ester derivative (II) include 2 (acryloxy) ethyltrimethylammonium chloride, 2 (methacryloxy) ethyltrimethylammonium chloride, 3 (acryloxy) propyltrimethylammonium chloride, 3 (methacryloxy) propyltrimethyl. Examples include ammonium chloride and 3 (methacryloxy) 2-hydroxypropyltrimethylammonium chloride.

Examples of the copolymerization component (second copolymerization component) that forms a copolymer with the first copolymerization component include butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxy. Propyl methacrylate, butylene glycol monoacrylate, butylene glycol monomethacrylate, ethyl acrylate, butoxyethyl acrylate, butoxyethyl methacrylate, ethoxybutyl acrylate, tetrahydrofurfuryl acrylate, glycerin monoacrylate, glycerin monomethacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate , Polypropylene glycol monoacrylate, polypropylene glycol monometa Relate, acrylamide, methacrylamide, N- dimethylacrylamide, N- diethyl acrylamide, N- butoxymethyl acrylamide,
Examples include dimethylaminopropyl methacrylamide, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, vinyl acetate, vinyl propionate, vinylpyrrolidone, and diacetone acrylamide. Two or more kinds of each of the first and second copolymerization components may be mixed.

Monomers having relatively low copolymerizability among the second copolymerization components are monomers having high copolymerization, such as butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, vinylpyrrolidone and acetic acid. vinyl,
It is recommended to mix it with and subject it to the copolymerization reaction described below.

The copolymer contains 20 to 80% by weight of the first copolymerization component and 80 to 20% by weight of the second copolymerization component. If the first copolymerization component is too small, conductivity is not substantially obtained, and if it is too large, the cohesive force of the obtained pressure-sensitive adhesive decreases.

The conductivity of the pressure-sensitive adhesive prepared using the copolymer is mainly due to the first copolymerization component in the copolymer. Therefore, the degree of conductivity of the pressure-sensitive adhesive is determined by both the ratio of the first copolymerization component in the copolymer and the ratio of the copolymer in the pressure-sensitive adhesive. For example, a copolymer having a relatively small amount of the first copolymerization component needs to be contained in a relatively large amount in the pressure-sensitive adhesive in order to secure conductivity. Conductivity is further related to ammonium nitrogen in the first copolymerization component.
When the molecular weight of the first copolymerization component is large, the proportion of ammonium nitrogen in the molecule is relatively small, so that it is necessary to increase the content of the first copolymerization component in order to obtain the necessary conductivity. The degree of conductivity also depends on the chemical structure of the first copolymerization component. When the first copolymerization component is a (meth) acrylamide derivative, the obtained adhesive has higher conductivity than when it is a (meth) acrylic acid ester derivative. Therefore, when the (meth) acrylic acid ester derivative is used, the amount of the first copolymerization component needs to be slightly increased. The first and second copolymerization components are each 2
One or more species may be mixed.

The first copolymerization component and the second copolymerization component (both are monomers) are subjected to a polymerization reaction by an ordinary radical polymerization method, for example, a solution polymerization method to obtain a copolymer. In the case of the solution polymerization method, a solvent that can dissolve each monomer to be used and the copolymer to be formed is used as the solvent. Such a solvent varies depending on the composition of the monomer used, but for example, alcohol, a water-alcohol mixed solution (alcohol is methanol, ethanol, isopropanol, etc.) is used.

To obtain the copolymer, for example, first, each of the above monomers and the solvent are charged into a reactor equipped with a reflux condenser. The monomer concentration is preferably 30 to 80%. Next, the inside of the reactor is replaced with an inert gas such as nitrogen, and the catalyst introduction is started while heating and stirring. As the catalyst, azobis type, peroxide type and the like which are usually used in the polymerization reaction are preferably used. The amount of catalyst is usually in the range of 0.1 to 1.0 mol% of the total number of monomers. The catalyst is appropriately divided into 1/20 to 1/5 of the total amount and added to the reaction solution. The catalyst feeding interval is preferably 0.2 to 1.5 times the half-life of the catalyst used.
The reaction temperature is usually 50-80 ° C. Especially when the charged concentration of the monomer is 50% or more, a runaway reaction or gelation should be prevented by the method of gradually decreasing the concentration by adding a solvent to the reaction system several times to dozens of times to reduce the viscosity. Is preferred. The reaction time varies depending on the monomer composition, type and amount of catalyst, reaction conditions, etc., but is usually about 20 to 50 hours. In this way, a viscous solution containing the copolymer is obtained.

The copolymer thus obtained is the main component of the pressure-sensitive adhesive. This copolymer may be tacky by itself depending on the kind and amount of the copolymerization component, but it is usually non-tacky, and in the dry state it is relatively brittle and hard resinous. In the dry state, conductivity is not exhibited. However, when water is added to this, the copolymer softens and becomes tacky, and functions as an adhesive. The internal cohesive force also becomes appropriate, and it has viscoelastic properties and exhibits conductivity.

The amount of water varies depending on the composition of the copolymerization components, the thickness of the pressure-sensitive adhesive layer, the desired degree of adhesion, etc.
It is in the range of 5 to 50 parts by weight with respect to parts by weight. The larger the proportion of the first copolymerization component in the copolymer, the larger the amount of water and the below-mentioned magnesium chloride for softening the copolymer. If the amount of water is too small, not only does the tackiness not appear, but also the conductivity cannot be obtained. If the copolymer contains water and softens and functions as an adhesive, the conductivity is sufficient. When the amount of water is excessive, the adhesiveness of the resulting pressure-sensitive adhesive increases, but it becomes soft and fluid.

The adhesive contains magnesium chloride in addition to the above copolymer and water. Magnesium chloride has a function of holding water in the adhesive at a predetermined ratio. For example, the presence of magnesium chloride prevents the moisture in the adhesive from disappearing due to evaporation. Even if the copolymer does not contain any water in a dry state, if magnesium chloride is contained, as a result of absorbing water in the air, the pressure-sensitive adhesive contains water in a certain proportion. The amount of magnesium chloride varies depending on the composition of the copolymer component, the thickness of the pressure-sensitive adhesive layer, the desired degree of tackiness, etc., but is usually in the range of 6 to 50 parts by weight per 100 parts by weight of the copolymer. If the amount is too small, not only the tackiness is not exhibited, but also the conductivity is not obtained. In some cases, the conductivity becomes unstable because water cannot be held at a constant rate. If it is excessive, the amount of water contained becomes excessive, so that it softens and becomes fluid.

The tackifier further contains a metal corrosion inhibitor, if necessary. Hydroquinone and / or corrosion inhibitors
Alternatively, a hydroquinone derivative is used. Examples of hydroquinone derivatives include hydroquinone monoalkyl ethers such as hydroquinone monomethyl ether, hydroquinone monoethyl ether, hydroquinone monopropyl ether, and hydroquinone monobutyl ether. These may be used as a mixture of two or more.

Such a corrosion inhibitor is usually blended in the adhesive in an amount of 15 parts by weight or less per 100 parts by weight of the copolymer. If it is excessive, the tackiness of the pressure-sensitive adhesive decreases. In addition, corrosion inhibitors can cause adhesives to cause skin irritation. To obtain the anticorrosion effect, usually 0.5 parts by weight or more of the anticorrosive agent is required. The adhesive with a corrosion inhibitor added in the range of 0.5 to 15 parts by weight does not corrode metals such as aluminum and tin at all, or has a slow corrosion rate to the extent that there is no practical problem when commercialized. Moreover, the conductivity and adhesiveness of the adhesive are not affected, and there is no irritation to the skin. Although the details of the mechanism of action of the corrosion inhibitor are unknown, it is believed that the corrosion inhibitor prevents or delays the corrosion reaction by trapping oxygen radicals and other radicals involved in the corrosion reaction which are considered to cause the corrosion reaction. Conceivable.

When the pressure-sensitive adhesive of the present invention contains, for example, a corrosion inhibitor, the content of the copolymer is usually 60 to 90% by weight in the total amount of the copolymer, water, magnesium chloride and the corrosion inhibitor. , 3 to 30% by weight of water and 4 of magnesium chloride
-40% by weight and 0.3-12% by weight of corrosion inhibitor.

In addition to the above-mentioned corrosion inhibitor, the adhesive may further contain a filler (filler), a strength adjusting agent (cohesive strength adjusting agent) when the adhesive is formed into a film, an adhesive adjusting agent, and a conductive property. Additives such as regulators are included. Of these, the filler is
There are inorganic fillers such as calcium carbonate, magnesium carbonate, zinc white, calcium chloride, talc and silicic acid anhydride; and organic fillers made of water-insoluble resin such as polystyrene, polymethylmethacrylate, polyamide, polyester and polyurethane. All the fillers are used in the form of fine powder. Film strength modifiers include polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, vinyl methyl ether-maleic anhydride copolymer, hydroxyethyl cellulose, sodium carboxymethyl cellulose, gum arabic, glue, tragacanth gum, karaya gum and the like. Examples of the adhesiveness adjusting agent include glycerin, diglycerin, polyethylene glycol, polypropylene glycol, butylene glycol, amylene glycol, trimethylolethane, sorbitol, diethanolamine, triethanolamine alkylsulfate, fatty acid diethanolamide, and aminoalkylpropanol. Examples of the conductivity adjusting agent include behenyltrimethylammonium chloride, lauryltrimethylammonium chloride, octadecyltrimethylammonium chloride and dimethyldodecylammonium acetic acid. The amount of the above additives varies depending on the individual, but is usually about 40% by weight of the total weight of the copolymer, water and magnesium chloride.
Below, preferably about 30% by weight or less. If it is excessive, for example, the adhesiveness and conductivity of the adhesive will be reduced.

To prepare the pressure-sensitive adhesive of the present invention, for example, first, a solvent is added to the copolymer solution prepared by the above-mentioned copolymerization reaction as needed to adjust the viscosity. Water, magnesium chloride, and if necessary, the above corrosion inhibitor, filler, film strength adjusting agent, etc. are added to this to obtain an adhesive solution. Magnesium chloride is a commercially available hexahydrate (Mg
It is convenient to use Cl ₂ · 6H ₂ O). Usually, magnesium chloride is added as a concentrated aqueous solution, and the corrosion inhibitor is added as a concentrated solution of water or alcohol. The amount of water may be excessive or insufficient, and after preparation of the pressure-sensitive adhesive, drying or humidity control is carried out to obtain a pressure-sensitive adhesive having desired adhesiveness.

The material of the electrode plate used for the medical adhesive electrode of the present invention includes tin, aluminum, nickel, lead, chromium, silver,
Gold, platinum, iron, copper and alloys of these are used. In particular, tin, aluminum and tin-aluminum alloy, which have excellent conductivity and are relatively inexpensive, are preferably used. An electrode plate is formed by using these metals as a metal foil having a thickness of 20 to 200 μm or as a laminate with a reinforcing backing member. The size of the electrode plate varies depending on its use, but in the case of an electrocardiograph electrode, its diameter is 20 to 50 mm. The reinforcing backing member is, for example, a film made of resin such as polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, nylon, polyurethane, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, and fibrin derivative. Or a sheet;
There are paper, woven and non-woven fabrics made of natural fibers and synthetic fibers. The reinforcing backing member itself may be a laminate.

In order to prepare an adhesive electrode, for example, the above-mentioned adhesive solution containing water, magnesium chloride, etc. added onto such a conductive base material is cast continuously or in a spot shape in accordance with a desired electrode size. . This is dried to such an extent that it has suitable tackiness, or completely dried to remove water and alcohol, and then left in an atmosphere of suitable humidity to absorb the water and develop the tackiness. A release paper is usually attached to the surface of the pressure-sensitive adhesive layer thus formed in order to protect the pressure-sensitive adhesive layer. To form the pressure-sensitive adhesive layer, the pressure-sensitive adhesive solution may be cast on a release paper, dried, and then transferred to the surface of the conductive substrate. The pressure-sensitive adhesive layer has a thickness of 100 to 1000 μm, preferably 100 to 600 μm. Even with such a relatively thin layer, sufficient tackiness can be obtained. The conductive base material on which the pressure-sensitive adhesive layer is formed in this manner is subjected to a punching process with the release paper applied, for example, to obtain a pressure-sensitive adhesive electrode having a desired shape. The conductive base material may be prepared into a desired shape and then the adhesive layer may be formed thereon.

As shown in FIGS. 1 and 2, the adhesive electrode 1 of the present invention
Is, for example, a disk-shaped metal foil electrode plate 11 and this electrode plate.
11 and a conductive adhesive layer 12 provided on one surface. Surface of conductive adhesive layer 12 (side contacting the skin surface of the measurement subject)
A release paper 13 that is thinly coated and cured with silicone or the like is attached to the. This release paper 13 is a conductive adhesive layer
It protects 12 and is peeled off when the electrode is attached to the skin. A protrusion 110 that protrudes outward is provided on a part of the electrode plate 11. No adhesive layer is provided on the protrusion 110, and as shown in FIG. 3, the protrusion 110 is electrically connected to the medical electric device 3 such as an electrocardiograph via a lead wire 31. . The conductor wire is connected to the projection 110 through a clip or the like. A laminate of a metal foil and a backing member can be used as the electrode plate. When using a laminate, the thickness of the metal foil is suitably 10 to 50 μm. As such an electrode, an electrode having the same structure as in FIGS. 1 and 2 can be used except that a laminate is used instead of the metal foil electrode plate 11. further,
As shown in FIGS. 4 and 5, the reinforcing backing member 211
2 of the electrode plate 21, which is a laminate of the metal foil 212 and the metal foil 212.
An electrode having a metal terminal 213 penetrating a part of 10 is also suitably used. The metal terminal 213 is formed of iron, nickel or the like having excellent conductivity. An insulating sheet 214 is adhered to a portion of the metal foil surface of the electrode plate 21 where the metal terminal 213 projects so as to prevent the metal terminal 213 from coming into contact with the skin. A metal terminal 213 protruding from the backing member surface of the protrusion 210
A conducting wire is connected to the tip of the electrode by a clip or the like, and the electrode 2 and the medical electric device are connected via the conducting wire. In FIG. 5, 22 and 23 indicate the adhesive layer and release paper, respectively, as in 12 and 13 of FIG.

(Operation) According to the present invention, as described above, an adhesive having excellent conductivity and adhesiveness can be obtained. The conductivity and the degree of tackiness of the pressure-sensitive adhesive can be adjusted by the composition of the copolymer used and the amount of magnesium chloride, and the desired pressure-sensitive adhesive can be easily obtained.
The copolymer can be easily prepared and the adhesive can be obtained at low cost. Since the adhesive electrode provided with the layer of the adhesive of the present invention on the surface of the electrode plate is excellent in conductivity, it is possible to obtain good measurement sensitivity when used in a measuring instrument such as an electrocardiograph. Such an electrode is extremely easy to use as compared with a conventional method of attaching the electrode using a conductive gel. The adhesive electrode can be easily prepared.

Since the adhesive to which the corrosion inhibitor is added does not corrode the metal, even if the electrode is stored for a long time, the electrode plate will not be corroded and the conductivity will not change, and the conductivity of the adhesive itself will not change. There is nothing to do. Since tin or aluminum, which has excellent conductivity but is relatively susceptible to corrosion, can be used as an electrode plate, a highly sensitive adhesive electrode can be prepared at low cost. Since the adhesive has no skin irritation, rash does not easily occur even if the electrode is applied to the skin surface for a long time.

(Examples) The present invention will be described with reference to Examples.

Example 1-1 (A) Preparation of adhesive: 42 parts by weight of 3 (methacrylamido) propyltrimethylammonium chloride as (meth) acrylamide derivative (first copolymerization component), second
58 parts by weight of butyl acrylate as a copolymerization component and ethyl alcohol-water mixture (90:10) as a solvent were charged into a reaction vessel equipped with a reflux cooling device to prepare a 50% solution. N
_The reaction was carried out at 50 ° C for 12 hours, at 60 ° C for 12 hours, and at 70 ° C for 24 hours under stirring in _two streams. As the polymerization catalyst, azobisisobutyronitrile was added in an amount of 0.
4% by weight of ethyl alcohol-ethyl acetate mixed solution (90:10)
Was dissolved in 0.4% by weight and used. Catalyst is 50 ℃
Was added to the reaction system every two hours at 6 hours, three times every four hours at 60 ° C, and seven times every three hours at 70 ° C. If the viscosity of the reaction solution increases significantly during the polymerization reaction, stirring may become difficult and gelation or runaway reaction may occur, so the reaction solution was diluted with a solvent. The resulting reaction solution was a viscous transparent solution. This reaction solution (copolymer solution) was diluted with a solvent to give a viscosity (polymer component 28 to 32%) suitable for compounding magnesium chloride described later.
30 parts by weight of magnesium chloride hexahydrate (MgCl ₂ · 6H ₂ O) (as MgCl ₂ ) based on 100 parts by weight of the polymer component of this solution
14 parts by weight) was added as a 60% aqueous solution to obtain an adhesive solution.

(B) Evaluation of adhesiveness of adhesive-A laminate of a 43 μm thick sheet of an alloy containing 60% by weight of lead and 40% by weight of tin and a sheet of 50 μm in thickness of polyethylene terephthalate (PET) is used as a conductive base material. did. The pressure-sensitive adhesive solution obtained in item (A) has a thickness of 180 to 2 on the metal surface of this conductive substrate.
It was cast to have a diameter of 00 μm. After drying it, it was left in a high-humidity atmosphere (70 to 75% RH) at room temperature again for humidity control. When the pressure-sensitive adhesive layer has suitable tackiness (when it has the best tackiness), stop the humidity control and cover the pressure-sensitive adhesive layer surface with a protective PET sheet to evaporate or absorb moisture. I tried not to happen. The protective sheet is a PET sheet surface coated with a silicone release agent and cured.

When the formed adhesive layer was touched with a finger, it was found to have excellent adhesiveness. The adhesive strength value of the adhesive layer was measured by the probe tack method (ASTM D 2979). Separately, the water content in the adhesive layer was measured by the heating weight loss method. The respective results are shown in Table 1. Examples 1-2 to 1-
The results of the item 5 (B) are also shown in Table 1. In the section of tackiness in Table 1, the mark ◯ means that the tackiness is excellent when touched with a finger.

(C) Conductivity evaluation of adhesive: An adhesive layer having a size of at least 2 cm × 2 cm is formed on the metal surface of the same conductive base material as used in (B) according to (B). The width of the part where the adhesive layer was not provided was 1 cm or more, and this was used as the lower electrode. Separately, a conductive base material (2 cm × 3 cm) of the same quality was prepared as the upper electrode, and a test piece was prepared by bringing the metal surface of the base material into close contact with the adhesive layer of the lower electrode so that the area of 2 cm / 2 cm was in contact with the adhesive layer. The remaining 1 cm portion of the upper electrode that was not in contact with the lower electrode adhesive layer was folded back 90 ° to form the upper electrode terminal, and the portion of the lower electrode on which the adhesive layer was not formed was the lower electrode terminal. Connect the lead wires to the upper and lower electrode terminals, respectively, and connect them through the adhesive layer.
A sinusoidal voltage of Hz and 10 mV was applied. The current value I flowing at that time was measured. The electrical resistance value R (impedance) of the test piece was calculated from this current value.

The above measurement was performed at 23 ° C. and 63% RH. The results are shown in Table 1. Examples 1-2 to 1-5 (C) and Comparative example 1-1
Table 1 also shows the results of items 1-2 (B).

Example 1-2 (A) Preparation of pressure-sensitive adhesive: A copolymer using 38 parts by weight of the first copolymerization component and 62 parts by weight of 2-hydroxypropyl acrylate as the second copolymerization component. Prepared, MgC
l ₂ · 6H ₂ O amount of 28 parts by weight of (MgCl ₂ as 13 parts by weight)
Other than the above, the procedure is the same as that in the example 1-1 (A).

(B) Evaluation of Adhesiveness of Adhesive: Using the adhesive obtained in the item (A) of this Example, the adhesiveness was evaluated according to the item (B) of Example 1-1.

(C) Conductivity evaluation of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity in accordance with Example 1-1 (C).

Example 1-3 (A) Preparation of adhesive: 2 (methacryloxy) ethyltrimethylammonium chloride as first copolymerization component
The copolymer was prepared by using 25 parts by weight and 25 parts by weight of 3 (acrylamido) propyltrimethylammonium chloride, and 20 parts by weight of 2-hydroxyethyl acrylate and 30 parts by weight of 2-hydroxypropyl acrylate as the second copolymerization component. Example 1 except that the amount of MgCl ₂ .6H ₂ O added was 35 parts by weight (16 parts by weight as MgCl ₂ )
This is the same as item 1 (A).

(B) Evaluation of Adhesiveness of Adhesive: Using the adhesive obtained in the item (A) of this Example, the adhesiveness was evaluated according to the item (B) of Example 1-1.

(C) Conductivity evaluation of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity in accordance with Example 1-1 (C).

Examples 1-4 (A) Preparation of PSA: 55 parts by weight of 3 (acrylamido) isopentyltrimethylammonium chloride as the first copolymerization component and 25 parts by weight of butyl acrylate as the second copolymerization component and acrylic acid 2 A copolymer was prepared using 20 parts by weight of hydroxyethyl, and the addition amount of MgCl ₂ .6H ₂ O was changed to 43 parts by weight (20 parts by weight as MgCl ₂ ) and Example 1-1 (A). It is the same as the item.

(B) Evaluation of Adhesiveness of Adhesive: Using the adhesive obtained in the item (A) of this Example, the adhesiveness was evaluated according to the item (B) of Example 1-1.

(C) Conductivity evaluation of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity in accordance with Example 1-1 (C).

Examples 1-5 (A) Preparation of adhesive: 3 (acryloxy) propyltrimethylammonium chloride as the first copolymerization component
A copolymer was prepared using 65 parts by weight, and 20 parts by weight of vinylpyrrolidone and 15 parts by weight of vinyl acetate as the second copolymerization component, and the addition amount of MgCl ₂ · 6H ₂ O was 50 parts by weight (as MgCl _2). 23 parts by weight) except that it is the same as in Example 1-1 (A).

(B) Evaluation of Adhesiveness of Adhesive: Using the adhesive obtained in the item (A) of this Example, the adhesiveness was evaluated according to the item (B) of Example 1-1.

(C) Conductivity evaluation of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity in accordance with Example 1-1 (C).

Comparative Example 1-1 (A) Preparation of adhesive: Polyvinylpyrrolidone (Kollidon)
A concentrated alcohol solution containing 100 parts by weight of K-90 (trade name) and 55 parts by weight of glycerin was prepared and used as an adhesive solution.

(B) Conductivity Evaluation of Adhesive: The adhesive obtained in the item (A) of this comparative example was used to evaluate the conductivity according to the item (C) of Example 1-1.

Comparative Example 1-2 (A) Preparation of adhesive: A concentrated alcohol solution containing 100 parts by weight of polyvinylpyrrolidone and 55 parts by weight of glycerin was prepared. A concentrated aqueous solution containing 20 parts by weight of sodium chloride was added to this to prepare an adhesive solution.

(B) Conductivity evaluation: Using the pressure-sensitive adhesive obtained in the item (A) of this comparative example, the conductivity was evaluated according to the item (C) of Example 1-1.

From Table 1, it can be seen that the conductive adhesive of the present invention has excellent adhesiveness and conductivity. When a pressure-sensitive adhesive electrode for electrocardiograph having a diameter of 3 cm was prepared using the pressure-sensitive adhesives of Examples 1-1 to 1-5,
The resistance value of the obtained electrode is calculated to be about 760 to 1160Ω.
Usually, if the resistance value of the electrocardiograph adhesive electrode is 4 kΩ or less, there is no practical problem, and it can be seen that the adhesive agent of the present invention has excellent conductivity even when compared with this value.

Example 2-1 (A) Preparation of pressure-sensitive adhesive: The same as in Example 1-1 (A) except that 2 parts by weight of hydroquinone as a corrosion inhibitor was further added to the polymer solution as a concentrated aqueous solution.

(B) Evaluation of the corrosiveness of the pressure-sensitive adhesive: The pressure-sensitive adhesive solution obtained in (A) was applied on a tin substrate and an aluminum substrate and dried to form a pressure-sensitive adhesive layer having a thickness of about 180 to 200 μm. .
The humidity was adjusted in the same manner as in Example 1 (B), and the pressure-sensitive adhesive layer was covered with a protective sheet. The tin base material used here has a thickness of 15 μm.
It is a laminate of the tin foil and a PET film with a thickness of 50 μm. The tin foil surface was preliminarily formed with cut lines at intervals of 3 mm only in the region where the adhesive layer was to be provided, and the adhesive layer was formed on this surface. A soft aluminum foil having a thickness of 30 μm was used as the aluminum substrate. Each substrate on which the pressure-sensitive adhesive layer was formed was left under the condition of 60 ° C and 75% RH, and the time required for the substrate to be corroded to a predetermined degree was measured. Here, "corrosion to a predetermined degree" means a state where the tin foil surface is corroded at a rate of 25% when a tin base material is used. When using aluminum base material, base material 10
The figure shows the state in which one hole is formed per cm ² . In this example, the sample was left for 240 hours, but neither the tin base material nor the aluminum base material was corroded to the above degree. The results of Examples 2-2 to 2-5 (B) are also shown in Table 2.

(C) Conductivity evaluation of pressure-sensitive adhesive: the pressure-sensitive adhesive solution obtained in this Example (A) and the same tin base material as used in this Example (B) (however, notched on the upper plate electrode) No line was formed) and a test piece was prepared according to the item (C) of Example 1 and the electric resistance value thereof was measured. Next, this test piece (B)
After storing under the same conditions as in the section (60 ° C, 75% RH), the impedance was calculated again after 240 hours of measurement. The results of the items of Examples 2-2 to 2-5 (C) are also shown in Table 2.

(D) Evaluation of Adhesiveness of Adhesive: The adhesiveness of the adhesive after storage under high temperature and high humidity was evaluated in the item (C) of this Example. The results are shown in Table 2. In Table 2, ○ indicates that the adhesiveness is almost the same as before the experiment, and △ indicates that the adhesiveness is
It indicates that the degree is considerably reduced. Example 2-
The results of the items 2 to 2-5 (D) are also shown in Table 2.

Example 2-2 (A) Preparation of adhesive: Example 1-2 (A) except that 5 parts by weight of hydroquinone monomethyl ether as a corrosion inhibitor was added to the polymer solution as a concentrated aqueous solution.
It is the same as the item.

(B) Evaluation of corrosiveness of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate corrosiveness according to Example 2-1 (B).

(C) Evaluation of conductivity of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity according to Example 2-1 (C).

(D) Evaluation of Adhesiveness of Adhesive: The adhesiveness of the adhesive after storage under high temperature and high humidity was evaluated in the item (C) of this Example.

Example 2-3 (A) Preparation of pressure-sensitive adhesive: Example 1-3 (A) except that 8 parts by weight of hydroquinone monoethyl ether as a corrosion inhibitor was added to the polymer solution as a concentrated aqueous solution.
It is the same as the item.

(B) Evaluation of corrosiveness of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate corrosiveness according to Example 2-1 (B).

(C) Evaluation of conductivity of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity according to Example 2-1 (C).

(D) Evaluation of Adhesiveness of Adhesive: The adhesiveness of the adhesive after storage under high temperature and high humidity was evaluated in the item (C) of this Example.

Example 2-4 (A) Preparation of pressure-sensitive adhesive: The same as in Example 1-4 (A) except that 8 parts by weight of hydroquinone as a corrosion inhibitor was further added to the polymer solution as a concentrated aqueous solution.

(B) Evaluation of corrosiveness of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate corrosiveness according to Example 2-1 (B).

(C) Evaluation of conductivity of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity according to Example 2-1 (C).

(D) Evaluation of Adhesiveness of Adhesive: The adhesiveness of the adhesive after storage under high temperature and high humidity was evaluated in the item (C) of this Example.

Example 2-5 (A) Preparation of pressure-sensitive adhesive: The same as in Example 1-5 (A) except that 11 parts by weight of hydroquinone as a corrosion inhibitor was further added to the polymer solution as a concentrated aqueous solution.

(B) Evaluation of corrosiveness of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate corrosiveness according to Example 2-1 (B).

(C) Evaluation of conductivity of pressure-sensitive adhesive: The pressure-sensitive adhesive obtained in this Example (A) was used to evaluate conductivity according to Example 2-1 (C).

(D) Evaluation of Adhesiveness of Adhesive: The adhesiveness of the adhesive after storage under high temperature and high humidity was evaluated in the item (C) of this Example.

Example 3-1 Using the pressure-sensitive adhesive obtained in Example 1-1, the corrosiveness, conductivity and tackiness of the pressure-sensitive adhesive were evaluated according to Example 2-1. The respective results are shown in Table 2.

Example 3-2 Using the pressure-sensitive adhesive obtained in Example 1-2, the corrosiveness, conductivity and tackiness of the pressure-sensitive adhesive were evaluated according to Example 2-1. The respective results are shown in Table 2.

Example 3-3 Using the pressure-sensitive adhesive obtained in Example 1-3, the corrosiveness, conductivity, and tackiness of the pressure-sensitive adhesive were evaluated according to Example 2-1. The respective results are shown in Table 2.

Example 3-4 Using the pressure-sensitive adhesive obtained in Example 1-4, the corrosiveness, conductivity, and tackiness of the pressure-sensitive adhesive were evaluated according to Example 2-1. The respective results are shown in Table 2.

Example 3-5 Using the pressure-sensitive adhesive obtained in Example 1-5, the corrosiveness, conductivity, and tackiness of the pressure-sensitive adhesive were evaluated according to Example 2-1. The respective results are shown in Table 2.

From Table 2, it can be seen that the conductive pressure-sensitive adhesive of the present invention to which the corrosion inhibitor is added does not corrode metals such as tin and aluminum, and the conductivity and the pressure-sensitive adhesiveness do not change. An adhesive electrode prepared using such an adhesive can be stored for a long period of time.

(Effects of the Invention) According to the present invention, as described above, an adhesive having excellent conductivity and adhesiveness can be obtained. The adhesive electrode of the present invention in which such an adhesive layer is provided on the surface of the electrode plate is excellent in adhesiveness to the skin and has excellent conductivity, and thus is suitable for medical measuring instruments such as an electrocardiograph. When used, good measurement sensitivity can be obtained. Since the adhesive with the corrosion inhibitor does not corrode the metal, the adhesive electrode can be stored for a long time.
As an electrode plate, it has excellent conductivity such as tin and aluminum.
Moreover, since a relatively inexpensive metal can be selected, a highly accurate electrode can be manufactured at low cost. Even if the electrode is stored for a long time, the conductivity of the electrode plate does not change due to corrosion of the electrode plate, and the conductivity of the adhesive itself does not change. Since the adhesive does not irritate the skin, rash does not easily occur even if the electrode is applied to the skin surface for a long time. Such an adhesive electrode can be widely used in medical electrical devices such as an electrocardiograph, an electromyography, an electroencephalograph, and a low-frequency therapeutic device.

[Brief description of drawings]

1 and 2 are respectively a plan view and a side view showing an example of the medical adhesive electrode of the present invention, FIG. 3 is an explanatory view showing a usage state of the adhesive electrode, and FIGS. 4 and 5 are respectively. It is a top view and a side view showing other examples of the medical adhesion electrode of the present invention. 1,2 …… Adhesive electrode, 11,21 …… Electrode plate, 12,22 …… Adhesive layer,
110,210 …… Protrusions.

Claims (9)

[Claims] 1. A medical conductive adhesive containing a polymer having a substituted ammonio group, water and magnesium chloride. 2. A (meth) acrylamide derivative having a chemical structure in which a group having a substituted ammonio group is bonded to a (meth) acrylamide group by an amide bond, and / or a group having a substituted ammonio group is (meth) acryloxy. A copolymer having a (meth) acrylic acid ester derivative having a chemical structure in which a group and an ester bond are combined, as a copolymerization component.
The adhesive according to item. 3. The polymer according to claim 1, wherein the water content is 5 to 50 parts by weight and the magnesium chloride content is 6 to 50 parts by weight with respect to 100 parts by weight of the polymer. Adhesive. 4. A polymer having a substituted ammonio group; water;
A medical conductive adhesive containing magnesium chloride; and a corrosion inhibitor composed of hydroquinone and / or a hydroquinone derivative. 5. A (meth) acrylamide derivative having a chemical structure in which a group having a substituted ammonio group is bonded to a (meth) acrylamide group by an amide bond, and / or a group having a substituted ammonio group is (meth) acryloxy. 5. A copolymer comprising a (meth) acrylic acid ester derivative having a chemical structure bonded to a group by an ester bond, as a copolymerization component.
The adhesive according to item. 6. The ratio of 5 to 50 parts by weight of the water and 6 to 50 parts of the magnesium chloride based on 100 parts by weight of the polymer.
The pressure-sensitive adhesive according to claim 4, wherein the corrosion inhibitor is contained in an amount of 0.5 to 15 parts by weight, and the corrosion inhibitor is contained in an amount of 0.5 to 15 parts by weight. 7. A medical adhesive electrode in which a conductive adhesive layer is provided on at least a part of an electrode plate, and the adhesive contains a polymer having a substituted ammonio group, water and magnesium chloride. Adhesive electrode. 8. A (meth) acrylamide derivative having a chemical structure in which a group having a substituted ammonio group is bonded to a (meth) acrylamide group by an amide bond, and / or a group having a substituted ammonio group is (meth) acryloxy. A copolymer having a (meth) acrylic acid ester derivative having a chemical structure in which a group and an ester bond are combined, as a copolymerization component.
The medical adhesive electrode according to the item. 9. The adhesive contains 5 to 50 parts by weight of the water and 6 to 50 parts by weight of the magnesium chloride based on 100 parts by weight of the polymer. Item 7. The medical adhesive electrode according to item 7.