JPH05161618A - Conductive tacky adhesive for medical purpose - Google Patents

Abstract

PURPOSE:To obtain excellent tacky adhesive power and electrical conductivity, low skin stimulating property and cell toxicity and good moldability by adding a conductive salt to a hydrogen bondable high-polymer complex consisting of a polymer having a hydrogen-donative amide group and a polymer having N-substd. lactam. CONSTITUTION:The conductive salt is added to the intramolecular hydrogen bondable high-polymer complex consisting of the polymer I contg. repeating unit having the hydrogen donative amide group expressed by formula I (R<1> and R<2> denote -H or -CH3; R<3> denotes any of -H, 1 to 5C alkyl group, phenyl group; Z denotes -COO-M<+> or -H. M<+> denotes any of a hydrogen ion, alkaline metal ion and ammonium ion) as one constituting component and the polymer II having the N-substd. lactam, by which the tacky adhesive for medical purposes is obtd. The ratio of the polymer I and the polymer II is preferably 1/0.2 to 0.1/1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical conductive adhesive which is excellent in conductivity and adhesive strength, has low skin irritation and is inexpensive.

[0002]

2. Description of the Related Art When using an electric medical instrument such as an electrocardiograph, an electroencephalograph, an electromyography, an electrode for detecting an electric signal is attached to the skin surface corresponding to a measurement site, and various electrodes are attached to the electrode. The measurement is performed by connecting to the medical electric device. Since an electrode for detecting an electric signal used for such a purpose needs to be electrically coupled to the skin surface, conventionally, a conductive paste cream is applied to the skin surface or the electrode, whereby the skin surface and the electrode are Electrical connection with has been measured. However, this method has a drawback in that it is necessary to wipe off the conductive paste cream adhering to the skin or the electrode after the measurement is completed, and the measurement work becomes complicated.

Therefore, in recent years, a conductive adhesive which is an alternative to the conductive paste cream has been developed, an adhesive electrode in which this conductive adhesive and an electrode are connected has been developed, and this adhesive electrode should be attached to the skin surface. This allows electrical connection between the electrode and the skin surface.

As a conductive adhesive material applied to such an adhesive electrode, for example, Japanese Patent Publication No. 60-153839 discloses a partial acid of a hydrophilic polymer containing a carboxyl group and a polyamine or polyammonium salt. A conductive adhesive comprising an amide cross-linking reaction product is disclosed. However, this conductive adhesive is, under water content, ethylenediamine, hexamine, triethylenetetramine,
1- (3-chloroallyl) -3,5,7-triaza-1
-Azo-adamantan chloride (CTAC), because it is synthesized by reacting with an amine compound such as polyethyleneimine and a carboxyl group-containing compound, unreacted (poly) amine remains in the conductive adhesive, causing skin irritation. The problem remains in sex, cytotoxicity, etc.

Further, Japanese Patent Publication No. 62-44933 discloses a (co) polymer obtained from 2-acrylazide-2-methylpropanesulfonic acid or a conductive pressure-sensitive adhesive comprising an ammonium or alkali metal salt thereof, and its weight. A conductive pressure-sensitive adhesive comprising a coalesce and a paste thickener such as polyvinylpyrrolidone is further disclosed in JP-B-63-30010, wherein a carboxylate-containing monomer comprising a Group I metal salt, an amine salt, and a quaternary ammonium salt. Conductive pressure-sensitive adhesives composed of a polymer containing as a repeating unit are disclosed, but these have residual monomers in the obtained conductive pressure-sensitive adhesives, and the conductive pressure-sensitive adhesives are crosslinked. Since the structure is not introduced, if the adhesive electrode is produced by applying this, there is a problem in the shape stability.

Further, Japanese Patent Application Laid-Open No. 62-321 discloses a conductive pressure-sensitive adhesive obtained by adding an ammonium salt to a pressure-sensitive adhesive base material such as polyvinylpyrrolidone, which is basically a non-hydrogen type. Since it is a substance, it has low conductivity, and since an ionic cross-linking agent such as dibutyltin dilaurate is used for the production, there are problems with skin irritation and cytotoxicity. On the other hand, conductive adhesives that use natural polymer polysaccharides such as karaya gum as an adhesive have also been proposed, but since this uses a natural product as an adhesive, the quality differs depending on the production area and manufacturing lot. In addition, it is not suitable for long-term use because it has problems such as weak sweating and generation of various bacteria.

[0007]

That is, in the conventional conductive adhesive, it is preferable to use a synthetic polymer in order to avoid variations in product quality among production lots and contamination by various bacteria. In order to produce a pressure-sensitive adhesive electrode that has shape stability after molding when a molecule is applied, it is essential to introduce a crosslinked structure into the polymer (adhesive). In order to introduce a crosslinked structure, it is necessary to add a polyfunctional monomer or an ionic crosslinkable compound as a crosslinking agent,
Purification becomes difficult because the product becomes insoluble by adding these, unreacted cross-linking agent inevitably remains in the obtained conductive adhesive, skin irritation due to these elution, It becomes a problem in terms of cytotoxicity.

Therefore, in order to obtain a conductive pressure-sensitive adhesive without elution of an active low-molecular compound, it is preferable that the polymers form a cross-linked structure by the mutual interaction between the molecules. An intermolecular hydrogen bond is one of such intermolecular interactions.

As the polymer complex by intermolecular hydrogen bond, carboxylic acid group (--COOH) such as polyacrylic acid, polymethacrylic acid, styrene-maleic acid alternating copolymer, etc.
And a polymer having an amide group such as polyacrylamide or polyvinylpyrrolidone or a polymer having an ether bond such as polyethylene oxide, an intermolecular hydrogen bond between the carboxylic acid group and the amide group or the ether bond oxygen. Forming, complexing,
It is known to gel (see Polymer Complex 5, “Polymer Assembly”, Academic Publishing Center 1983, etc.).
However, in these systems, when each raw material compound solution is mixed, it instantly gels, so it is difficult to mold it into a desired shape, and it is difficult to apply it as a conductive adhesive, particularly as a medical conductive adhesive. ..

An object of the present invention is to solve the above-mentioned problems of the prior art, and has excellent adhesive strength, conductivity, low skin irritation and cytotoxicity, and good moldability.
An object of the present invention is to provide a medical conductive adhesive having excellent shape stability when molded into an adhesive electrode or the like.

[0011]

In order to solve the above-mentioned problems, the inventors of the present invention have conducted extensive studies and as a result, as a result, a polymer I having a primary or secondary amide group as a hydrogen-donating group.
By adding a conductive salt to the hydrogen-bonding polymer complex composed of the polymer II having N-substituted lactam, the adhesiveness, moldability, and shape stability after molding are excellent, and the conductivity is high. It was found that an excellent conductive adhesive can be obtained,
The present invention has been completed. That is, the present invention is

[Chemical 2] (In the formula, R ¹ and R ² are —H or —CH
₃ , R ³ represents —H, an alkyl group having 1 to 5 carbon atoms or a phenyl group, and Z represents —COO ⁻ M ⁺ or —H. Note that M ⁺ represents any one of hydrogen ion, alkali metal ion, and ammonium ion. ), A conductive salt is added to an intermolecular hydrogen-bonding polymer complex consisting of a polymer I having a repeating unit having a hydrogen-donating amide group as a constituent and a polymer II having an N-substituted lactam. A medical conductive adhesive is provided.

The polymer II is preferably polyvinylpyrrolidone.

Further, it is preferable that R ¹ , R ² , R ³ and Z of the polymer I are —H.

Further, R ¹ , R ² and R of the polymer I are
^It is preferred that ³ is -H and Z is -COO ^- M ⁺ .

The polymer I is ethylene and / or
Alternatively, it is preferably a polymer having an amide group on the side chain obtained by reacting a copolymer of substituted ethylene and maleic anhydride with ammonia.

The amount ratio of the polymer I and the polymer II is preferably 1 / 0.2 to 0.1 / 1.

The content of the conductive salt is preferably 1 to 50 parts by weight with respect to the intermolecular hydrogen-bonding polymer complex composed of the polymer I and the polymer II.

The medical conductive adhesive of the present invention will be described in detail below. The polymer I in the medical conductive adhesive of the present invention is

[Chemical 3] (In the above formula, R ¹ and R ² are —H or —CH.
₃ , R ³ represents —H, an alkyl group having 1 to 5 carbon atoms or a phenyl group, and Z represents —COO ⁻ M ⁺ or —H. Note that M ⁺ represents any one of hydrogen ion, alkali metal ion, and ammonium ion. ) Is a repeating unit having a first or second amide group represented by the formula (1).

In the above formula, R forming an amide group
³ is -H, an alkyl group having 1 to 5 carbon atoms, or a phenyl group. When the alkyl group has more than 5 carbon atoms, it interferes with intermolecular hydrogen bonding with the polymer II described later, and a good crosslinked structure cannot be obtained. In order to obtain a good crosslinked structure, a —H group is particularly preferably exemplified as R ³ .

The repeating unit represented by the formula constituting the polymer I is a case where Z and R ¹ are -H, Z is -COO ^- divided into a case of M ^+.

Where Z and R ¹ are --H,
That is, the polymer I

[Chemical 4] When the repeating unit represented by (hereinafter, referred to as a unit a) is a constituent component, specific examples of the monomer for introducing this unit include (meth) acrylamide and N-methyl (meth). Preferable examples include N-alkyl (meth) acrylamides such as acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-phenyl (meth) acrylamide and the like.

In particular, R ¹ , R derived from acrylamide
^A repeating unit in which ² , R ³ and Z are —H, that is, the following formula

[Chemical 5] The repeating unit represented by is preferably exemplified.

When the unit a is a repeating unit and constitutes one component, the polymer I is a homopolymerization of the above-mentioned monomers, or a copolymerization of two or more kinds of the above-mentioned monomers, and further Z is described below. It is provided by a copolymer having an amide group represented by the formula of —COO ⁻ M ⁺ as a repeating unit and a copolymer having no hydrogen-donating amide group.

The monomers having no hydrogen-donating amide group applicable in this case include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic. (Meth) acrylic acid and its esters such as propyl acrylate and butyl (meth) acrylate;
Vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate; sulfonic acid compounds such as vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether; N , (Meth) acrylamides having a third amide such as N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide and N-morpholyl (meth) acrylamide; vinylpyridine, vinyl chloride, vinylidene chloride, Preferable examples are styrene and (meth) acrylonitrile.

When the polymer I having the unit a as a constituent component contains a monomer having no hydrogen-donating amide group, a copolymer of the monomer having no hydrogen-donating amide group in the polymer I is used. The polymerization composition ratio is preferably about 0 to 80 mol%.
If the amount of the monomer having no hydrogen-donating amide group in the polymer I exceeds 80 mol%, the intermolecular hydrogen bonding force with the polymer II described later becomes weak, and, for example, when used as an adhesive electrode,
Sufficient shape retention cannot be obtained. The copolymerization composition ratio of the monomer having no hydrogen donating amide group is preferably about 0 to 60 mol%.

On the other hand, when Z is --COO ^-- M ^+, that is, the polymer I is

[Chemical 6] When the repeating unit represented by the formula (hereinafter referred to as unit b) is used as one constituent, this constituent is a dicarboxylic acid anhydride having an unsaturated bond such as maleic anhydride, fumaric anhydride, and citraconic anhydride. It can be obtained by reacting a homopolymer or a copolymer with ammonia or a monoalkylamine such as methylamine or ethylamine.

Further, a monomer represented by the following formula

[Chemical 7] (In the above formula, R ⁴ , R ⁵ and R ⁶ represent —H or —CH ₃ , and M represents any one of —H, ammonium ion and alkali metal ion). It may be one.

The repeating unit b is such that R ¹ , R ² and R ³ are -H and Z is -COO ^- M ⁺ . That is,

[Chemical 8] The repeating unit represented by is particularly preferably exemplified.

When the unit b is a repeating unit and constitutes one component, the polymer I is a homopolymer of one repeating unit b, a copolymer of a plurality of types of one repeating unit b, and Is provided by copolymerization with the above-mentioned unit a as a repeating unit or with a monomer having no hydrogen donating amide group.

The monomers having no hydrogen-donating amide group applicable in this case include unsaturated hydrocarbons such as ethylene, propylene, butene, pentene and styrene; vinyl formate, vinyl acetate and the like. Vinyl esters;
Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate and the like (Meth) acrylic acid and its esters; allyl compounds such as allyl alcohol, allyl ether, allyl acetate; sulfonic acid compounds such as vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid;
N, N-dimethyl (meth) acrylamide, N, N-
Preferable examples are (meth) acrylamides having a tertiary amide such as diethyl (meth) acrylamide and N-morpholyl (meth) acrylamide; and vinylpyridine, vinyl chloride, vinylidene chloride, (meth) acrylonitrile and the like.

When the polymer I containing the repeating unit of the unit b as a constituent component contains a monomer having no hydrogen-donating amide group, maleic anhydride and isobutylene, maleic anhydride and styrene, Maleic anhydride and ethylene,
Those derived from a 1: 1 alternating copolymer such as maleic anhydride and vinyl methyl ether are preferably applied in terms of easiness of synthesis and the like.

When the polymer I having the unit b as a constituent contains a monomer having no hydrogen-donating amide group, a copolymer of the monomer having no hydrogen-donating amide group in the polymer I is used. The polymerization composition ratio is preferably about 0 to 80 mol%. If the amount of the above-mentioned monomer in the polymer I exceeds 80 mol%, the intermolecular hydrogen bonding force with the polymer II described later becomes weak and, for example, when it is used as an adhesive electrode, sufficient shape retention cannot be obtained. .. The copolymerization composition ratio of the monomer having no hydrogen donating amide group is more preferably 0 to 6
It is about 0 mol%.

[0033] In the case where the polymer I is a constituent component a repeating unit of the units b is included in the unit b ⁺ M ^- OO
When C- is an acid type (-COOH), this constituent component becomes acidic, which is not preferable from the viewpoint of skin irritation and the like. Therefore, in this case, it is desired that at least a part of the constituent components is neutralized with an alkali.

The alkali to be applied includes, in addition to alkali metal hydroxide, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, etc. And the like are preferably exemplified. In particular, when the constituent component of the repeating unit of the unit b is derived from a (co) polymer of an acid anhydride such as maleic anhydride, a primary amine such as ammonia, methylamine or ethylamine is used to form an anhydrous ring. Aminolysis produces a hydrogen-donating amide group, and at the same time, the carboxylic acid moiety is neutralized to produce the polymer I, which is preferable from the viewpoint of easiness of synthesis.

The polymer I may be composed of a component consisting of repeating units containing the units a and b, and for example, a copolymer of ethylene and / or substituted ethylene and maleic anhydride may be used. Examples thereof include polymers having an amide group in the side chain obtained by reacting with ammonia.

There is no particular limitation on the molecular weight of the polymer I having one repeating component of the unit a and the repeating unit b, or the repeating unit of the unit including the unit a and the repeating unit b as a constituent. It is usually 10,000 or more, preferably 30,000 or more. By setting the molecular weight to 10,000 or more, a suitable intermolecular hydrogen bonding force can be obtained, and good shape stability can be secured after molding into an adhesive electrode or the like.

The medical conductive adhesive of the present invention forms an intermolecular hydrogen-bonding polymer complex with such a polymer I and a polymer II having an N-substituted lactam. Here, in the polymer II of the present invention, a hydrogen-accepting amide group is obtained by a lactam, and the third amide group is N,
It should be a tertiary amide group based on an N-substituted lactam, rather than a tertiary amide group such as N-dimethyl (meth) acrylamide. Regarding this point, a specific example will be shown later in Examples.

Examples of the lactam in the polymer II having an N-substituted lactam include pyrrolidone, piperidone, caprolactam and the like. The polymer II is obtained by polymerizing a monomer having a polymerizable substituent as the N-substituent of the lactam.

Specific examples of such a monomer include N
-Vinylpyrrolidone, N-vinylpiperidone, N-vinylcaprolactam, (meth) acrylamidoethylpyrrolidone, (meth) acrylamidoethylpiperidone, N
-2 [(meth) acryloxyethyl] pyrrolidone, N-
Preferable examples include 2 [(meth) acryloxybutyl] pyrrolidone. Above all, polyvinylpyrrolidone obtained by polymerizing N-vinylpyrrolidone is preferably applied. The polymer II may be a copolymer of two or more of these monomers.

The polymer II may be a copolymer of the above-mentioned monomer having an N-substituted lactam and a monomer not having an N-substituted lactam. Specific examples of the monomer having no N-substituted lactam include vinyl formate, vinyl acetate,
Vinyl esters such as vinyl propionate; (meth)
Acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth)
(Meth) acrylic acid and its esters such as butyl acrylate; ethylene, propylene, butene, pentene,
Unsaturated hydrocarbons such as styrene; (meth) acrylamides having a tertiary amide such as N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-morpholyl (meth) acrylamide;
Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; sulfonic acid compounds such as vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid; vinyl pyridine, vinyl chloride, vinylidene chloride, (meth) acrylonitrile, etc. It is preferably exemplified.

When the polymer II contains a monomer having no N-substituted lactam, the copolymer composition ratio of this monomer in the polymer II is preferably about 0 to 70 mol%. In the polymer I, the monomer having no N-substituted lactam is 7
If it exceeds 0 mol%, the intermolecular hydrogen bonding force with the above-mentioned polymer I becomes weak and, for example, when it is used as an adhesive electrode or the like, sufficient shape retention cannot be obtained.

The molecular weight of the polymer II is not particularly limited, but it is preferably 5,000 or more. By setting the molecular weight to 5,000 or more, a suitable intermolecular hydrogen bonding force can be obtained, and good shape stability can be secured after molding to an adhesive electrode or the like. The content ratio of the polymer I and the polymer II in the medical conductive adhesive of the present invention is a polymer I / polymer II = 1 / 0.2 to 0.1 / 1 by weight ratio, preferably the polymer I / polymer II = 1 / 0.4 to 0.2 / 1.

The medical conductive adhesive of the present invention comprises an intermolecular hydrogen-bonding polymer complex of polymer I and polymer II as described above.
A conductive salt is added. Applicable conductive salts include LiCl, NaCl, KCl, NH ₄ Cl, MgCl ₂ , CaCl ₂ , LiHC
O ₃ , NaHCO ₃ , KHCO ₃ , NH ₄ HCO ₃ , Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , (NH ₄ ) _{2
CO 3, Li 2 SO 4,} Na 2 SO 4, K 2 SO 4, (NH 4) 2 SO 4, LiNO 3, NH 4 NO 3,
Inorganic acid salts such as NaNO ₃ , KNO ₃ , Na ₂ HPO ₄ , K ₂ HPO ₄ ; sodium acetate, ammonium acetate, potassium acetate, sodium citrate, potassium citrate, sodium lactate, potassium lactate, sodium malate, malic acid Preferable examples include organic acid salts such as potassium; salts of polyamines such as polyethyleneimine hydrochloride, polyallylamine hydrochloride and ethylenediamine hydrochloride; salts of polyanions such as sodium polyacrylate, sodium polyvinylsulfate and sodium carboxymethylcellulose. To be done. Among them, sodium chloride, ammonium chloride, potassium chloride and the like are preferably applied.

The amount of the conductive salt added is not particularly limited, but if an excessive amount of the conductive salt is added, the intermolecular hydrogen bond between the polymer I and the polymer II may be changed by the ion of the conductive salt. It is cut, and it becomes impossible to obtain sufficient shape retention. Therefore, the amount of the conductive salt added is appropriately set depending on the composition of each polymer, the content ratio, and the like, but usually 100 weight% of the intermolecular hydrogen-bonding polymer complex composed of the polymer I and the polymer II is used. The amount is preferably about 1 to 50 parts by weight, and particularly preferably about 5 to 30 parts by weight.

The method for producing the medical conductive adhesive of the present invention containing such a polymer I, a polymer II and a conductive salt is not particularly limited, but the following method is preferably exemplified. .. First, 5 parts of Polymer I was added to 100 parts by weight of water.
.About.50 parts by weight, polymer II 10 to 100 parts by weight, and conductive salt 1 to 50 parts by weight are dissolved at room temperature. Then
This solution is poured into a mold having a predetermined shape, and 30 to 80
It may be heated at 2 ° C. for 2 to 10 hours for gelation and taken out from the mold after the heating is completed. The amount ratio of each polymer and the conductive salt may be appropriately set depending on the required adhesiveness, the hardness of the adhesive, and the like.

In the medical conductive adhesive of the present invention, a polymer I having a repeating unit having a hydrogen-donating amide group as a constituent, a polymer II having an N-substituted lactam, and a conductive salt are dissolved. Although the mechanism of gelation of an aqueous solution by heating has not been fully clarified, the present inventors presume as follows.

In the polymer I having a hydrogen-donating amide group in its constituent components, the amide group is considered to be mainly involved in the intramolecular hydrogen bond in an aqueous solution.
Therefore, even if the polymer II having an N-substituted lactam is mixed and dissolved in the constituents in this state, it remains a relatively stable aqueous solution at room temperature. However, when this aqueous solution is heated, the intramolecular hydrogen bond in the polymer I is broken,
It is considered that an intermolecular hydrogen bond is newly formed between the hydrogen of the amide group of the polymer I and the amide group of the polymer II, and both are physically cross-linked to gel. The fact that this gelation is not due to the formation of cross-linking points by covalent bonding means that the gelation does not proceed when an excessive amount of the conductive salt is added as described above, and that the obtained gel is regenerated into a large amount of hot water. Dissolving suggests clearly.

Therefore, according to the medical conductive adhesive of the present invention, it is not necessary to add a cross-linking agent during the production of the medical conductive adhesive, and skin irritation and cytotoxicity due to elution of unreacted residual cross-linking agent is achieved. It is possible to obtain an excellent medical conductive adhesive without the problem of

In the medical conductive adhesive of the present invention, a crosslinked structure may be introduced by radiation such as γ-rays. In this case, the gel strength (after molding) does not occur without causing problems such as elution of the crosslinking agent. The shape maintaining property) can be improved. Further, as described above, the medical conductive adhesive of the present invention originally does not require a cross-linking agent, but if necessary, an epoxy type,
You may add an isocyanate type crosslinking agent.

The medical conductive adhesive of the present invention may optionally contain a third component for the purpose of improving the moisturizing property. Examples of the third component that can be added include glycerin, diglycerin, propylene glycol, ethylene glycol, diethylene glycol, butylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, triethanolamine and salts thereof, diethanolamine and salts thereof, sorbitol and the like. It is illustrated. Two or more kinds of such third components may be added. The addition amount may be appropriately determined depending on the composition and the blending amount of the polymers I and II.

Basically, the medical conductive adhesive of the present invention having such a constitution has good adhesive strength and conductivity, and further has a shape-maintaining power after molding, and also has skin irritation and cell There are no problems such as toxicity. In addition, it is cheap and economical. Therefore, it is preferably applied to various medical applications such as an adhesive electrode of an electrocardiograph, an electroencephalograph, an electromyography, and the like.

FIG. 1 shows an example of an adhesive electrode to which the medical conductive adhesive of the present invention is applied. The adhesive electrode 10 shown in FIG. 1 includes an adhesive conductive layer 12 made of the medical conductive adhesive of the present invention and a backing layer 14 supporting the adhesive conductive layer 12.
And an electrode projection 16 and the electrode projection 16 is connected to an electrocardiograph, an electroencephalograph, and an electromyography, and the adhesive conductive layer 12 is attached to a measurement site of a subject (patient) to obtain an electroencephalogram. Etc. are measured. The backing layer 14 is formed of a known material such as foamed polyurethane.

Such an adhesive electrode 10 is composed of the adhesive conductive layer 1
Since the medical conductive adhesive of the present invention is applied to No. 2, it has good conductivity and excellent adhesive strength and does not adversely affect the skin of the patient. Moreover, since it is inexpensive, it can be suitably applied to disposable applications. Further, the medical conductive adhesive of the present invention may be used in combination with other adhesives or adhesive tapes as needed. The medical conductive adhesive of the present invention can be sterilized by γ-ray sterilization when directly used on the human body like the above-mentioned adhesive electrode.

[0054]

EXAMPLES The present invention will be described in more detail with reference to specific examples of the present invention.

Synthesis and Structure Confirmation of Polymer I [Synthesis Example 1] Synthesis and Structure Confirmation of Polymer I-1 Using Styrene-Maleic Anhydride Alternating Copolymer Styrene-Maleic Anhydride Alternating Copolymer (Aldrich Co. 10 g of distilled water) was dispersed in 100 g of distilled water, 30 ml of concentrated aqueous ammonia (ammonia content 28%) was added with stirring, and the mixture was heated to 90 ° C. and stirred until completely dissolved to obtain a viscous solution. This viscous solution was dropped into 1 liter of methanol under stirring to precipitate and precipitate the polymer, followed by vacuum drying overnight at 50 ° C. to obtain a polymer sample. As a result of infrared absorption spectrum analysis of the obtained polymer sample, the absorption derived from the carbonyl group of the first amide was 1667 cm.
^-1 , and the absorption derived from the carboxylate group is 15
It was observed at 59 cm ^-1 and was confirmed to be the polymer I of the present invention.

Synthesis Example 2 Synthesis and Structure Confirmation of Polymer I-2 Using Isobutylene-Maleic Anhydride Alternating Copolymer The styrene-maleic anhydride alternating copolymer of Synthetic Example 1 was replaced with isobutylene-maleic anhydride alternating copolymer. Copolymer (made by Kuraray
Isoban IBM-10) except that the above Synthesis Example 1 was used.
Polymer I-2 was obtained in the same manner as. The polymer infrared absorption spectrum analysis of the result of the absorption derived from the carbonyl group of the first amide in 1662Cm ^-1, also absorption derived from carboxylate groups was observed at 1555cm ^-1, in the present invention It was confirmed to be polymer I.

[Synthesis Example 3] Synthesis and structure confirmation of polymer I-3 using a methyl vinyl ether-maleic anhydride alternating copolymer 20 g of a methyl vinyl ether-maleic anhydride alternating copolymer (GANZLET AN139 manufactured by GAF) is used. Add 220 ml of concentrated aqueous ammonia (ammonia content 28%),
Stir and dissolve. After the copolymer is completely dissolved, 50 ~
It was heated to 70 ° C. and kept for 1 hour. After the temperature was lowered to room temperature, it was neutralized with hydrochloric acid, and the reaction solution was added dropwise to 3 l of methanol to precipitate and deposit a polymer. The polymer thus obtained was placed in 1 liter of methanol and washed by stirring overnight overnight to remove ammonium chloride in the polymer. The washed polymer was dried under reduced pressure at 50 ° C. overnight to obtain a polymer sample. Infrared absorption spectrum analysis of the result of the obtained polymer samples, absorption derived from a carbonyl group of the first amide in 1669Cm ^-1, also absorption derived from carboxylate groups was observed at 1565cm ^-1, It was confirmed to be polymer I in the present invention.

[Synthesis Example 4] Synthesis and structure confirmation of Polymer I-4 using ethylene-maleic anhydride alternating copolymer Synthesis Example 3 Ethylene-maleic anhydride alternating copolymer of methyl vinyl ether-maleic anhydride alternating copolymer Polymer I-4 was obtained in the same manner as in Synthesis Example 3 except that the copolymer was changed to Aldrich. The polymer infrared absorption spectrum analysis of the result of the absorption derived from the carbonyl group of the first amide to 1665 cm ^-1, also absorption derived from carboxylate groups was observed at 1557cm ^-1, in the present invention It was confirmed to be polymer I.

Confirmation Example 1 Structure Confirmation of Ammonia-Modified Isobutylene-Maleic Anhydride Alternating Copolymer Infrared ray was used to confirm the structure of ammonia-modified isobutylene-maleic anhydride alternating copolymer (Kuraray Isoban IBM-110). Absorption spectrum analysis was performed. As a result, the absorption derived from the carbonyl group of the first amide is 166.
To 2 cm ^-1, also the absorption was observed at 1555cm ^-1, which derived from carboxylate groups, the polymer I in the present invention
Was confirmed.

Synthesis of Medically Conductive Adhesive [Example 1] As Polymer I, 15 parts by weight of Polymer I-2 obtained from the isobutylene-maleic anhydride alternating copolymer synthesized in Synthesis Example 2 was added. As a combined II, 62 parts by weight of polyvinylpyrrolidone (K30 manufactured by Nacalai Tesque), 2 parts by weight of lithium chloride as a conductive salt, and 15 parts by weight of glycerin 20 ml were mixed with 100 parts by weight of distilled water.
Dissolved. The viscous solution thus obtained was degassed in vacuum, then cast to a thickness of 5 mm, sealed so that water would not evaporate, and kept at 50 ° C. for 24 hours to obtain the medical conductive material of the present invention. A sheet-shaped sticky material made of the sticky agent was obtained. This sheet was punched into a circle having a diameter of 20 mm, and the obtained circular sheet was placed on a silver-silver chloride electrode to give an adhesive electrode. When this adhesive electrode was pasted together and the AC impedance between the electrodes was measured based on ANSI at 10Hz, it was 0.13k.
It was Ω. The DC offset was 1.6 mV.

Example 2 A sheet of the medical conductive adhesive of the present invention was manufactured in exactly the same manner as in Example 1 except that lithium chloride was changed to magnesium chloride. When the same inspection was performed using the obtained sheet, the AC impedance was 0.12 kΩ and the DC offset was 1.6 mV.

[Example 3] As polymer I, the above-mentioned confirmation example 1
Ammonia-modified isobutylene-maleic anhydride alternating copolymer whose structure was confirmed by (Kuraray Isoban IBM
-110) 19 parts by weight, 67 parts by weight of polyvinylpyrrolidone (K30 manufactured by Nacalai Tesque) as polymer II,
As a conductive salt, 1.9 parts by weight of sodium chloride and 15 parts by weight of glycerin were mixed and dissolved in 100 parts by weight of distilled water. After defoaming this aqueous solution, it was left at 60 ° C. for 16 hours to obtain a light yellow transparent sheet-like pressure-sensitive adhesive gel with the medical conductive pressure-sensitive adhesive of the present invention. This sheet-shaped pressure-sensitive adhesive gel had tackiness, and there was no adhesive residue when it was peeled off after being attached to the skin. Further, when an adhesive electrode similar to that of Example 1 was produced using this sheet-like adhesive gel and was attached to the lower arm at an interval of 10 cm to form an electrode, the AC impedance at 10 Hz was 109 kΩ.

Example 4 As polymer I, the confirmation example 1
Ammonia-modified isobutylene-maleic anhydride alternating copolymer whose structure was confirmed by (Kuraray Isoban IBM
-110), 25 parts by weight of polyvinylpyrrolidone (K30 manufactured by Nacalai Tesque) as polymer II, 26.1 parts by weight of sodium chloride as a conductive salt, and 21.5 parts by weight of sorbitol as a moisturizer. It was mixed and dissolved in 100 parts by weight of distilled water. Using this solution, a gel was obtained in the same manner as in Example 3. This gel was tacky and had no adhesive residue when it was peeled off after being applied to the skin. Moreover, when the AC impedance was measured in the same manner as in Example 3, it was 43.5 kΩ.

Example 5 As Polymer I, 20 parts by weight of Polymer I-1 obtained from the styrene-maleic anhydride alternating copolymer synthesized in Synthesis Example 1 above, and as Polymer II, polyvinylpyrrolidone ( 40 parts by weight of K30) manufactured by Nacalai Tesque, 3 parts by weight of sodium chloride as a conductive salt, and 10 parts by weight of glycerin as a moisturizer are added to 100 parts of distilled water.
It dissolved in parts by weight. After degassing this aqueous solution, the solution is kept at 60 ° C for 20
After leaving for a time, a light yellow transparent sheet-like pressure-sensitive adhesive gel with the medical conductive pressure-sensitive adhesive of the present invention was obtained. This gel was tacky and had no adhesive residue when it was peeled off after being applied to the skin. The AC impedance measured in the same manner as in Example 3 was 35 kΩ.

Example 6 As Polymer I, 20 parts by weight of Polymer I-3 obtained from the alternate copolymer of methyl vinyl ether-maleic anhydride synthesized in Synthesis Example 3 above, and as Polymer II, polyvinylpyrrolidone 40 parts by weight (K30 manufactured by Nacalai Tesque), 3 parts by weight of sodium chloride as a conductive salt, and 10 parts by weight of glycerin as a moisturizer were dissolved in 100 parts by weight of distilled water. After degassing this aqueous solution,
It was left at 60 ° C. for 20 hours to obtain a light yellow transparent sheet-like pressure-sensitive adhesive gel of the medical conductive pressure-sensitive adhesive of the present invention. This gel was tacky and had no adhesive residue when it was peeled off after being applied to the skin. The AC impedance measured in the same manner as in Example 3 was 30 kΩ.

[Example 7] 15 parts by weight of polyvinylpyrrolidone (K30 manufactured by Nacalai Tesque) as polymer II was added to 60 parts by weight of an aqueous 10% polyacrylamide solution (manufactured by Wako Pure Chemical Industries, Ltd.) containing polyacrylamide as a polymer I. As a conductive salt, 3 parts by weight of sodium chloride was dissolved. After defoaming this aqueous solution, it was left at 60 ° C. for 40 hours to obtain a light yellow transparent sheet-like pressure-sensitive adhesive gel with the medical conductive pressure-sensitive adhesive of the present invention. This gel was tacky and had no adhesive residue when it was peeled off after being applied to the skin. The AC impedance measured in the same manner as in Example 3 was 29 kΩ.

Example 8 As Polymer I, 20 parts by weight of Polymer I-4 obtained from the ethylene-maleic anhydride alternating copolymer synthesized in Synthesis Example 4 above, and as Polymer II, polyvinylpyrrolidone ( 40 parts by weight of K30) manufactured by Nacalai Tesque and 3 parts by weight of sodium chloride as a conductive salt were dissolved in 100 parts by weight of distilled water. After degassing this aqueous solution,
It was left at 0 ° C. for 40 hours to obtain a light yellow transparent sheet-like pressure-sensitive adhesive gel of the medical conductive pressure-sensitive adhesive of the present invention. This gel was tacky and had no adhesive residue when it was peeled off after being applied to the skin. The AC impedance measured in the same manner as in Example 3 was 35 kΩ.

Comparative Example 1 As polymer I, 5 parts by weight of an amido ammonium salt derived from a polyvinyl methyl ether-maleic anhydride alternating copolymer, and as polymer II were 20 parts by weight of polyvinylpyrrolidone (K30 manufactured by Nacalai Tesque). Parts were dissolved in 50 parts by weight of distilled water. This solution was transferred to a container lined with release paper and left at 60 ° C. for 16 hours to obtain a light yellow transparent sheet-like adhesive gel. Using this gel, a pressure-sensitive adhesive electrode similar to that of Example 1 was produced, and AC impedance was measured in the same manner, and it was 0.13 kΩ.

[Comparative Example 2] As Polymer I, the above-mentioned Confirmation Example 1
20 parts by weight of an ammonia-modified isobutylene-maleic anhydride alternating copolymer, the structure of which was confirmed by, and polyvinylpyrrolidone as a polymer II (K30 manufactured by Nacalai Tesque)
Was mixed and dissolved in 100 parts by weight of distilled water.
Using this aqueous solution, a sheet-shaped pressure-sensitive adhesive gel was obtained in the same manner as in Example 1. Using this gel, in the same manner as in Example 3, A
When the C impedance was measured, it was 140 kΩ.

[Comparative Example 3] Synthesis Example 1 as Polymer I
5 parts by weight of the polymer I-1 obtained from the styrene-maleic anhydride alternating copolymer synthesized in Step 1, and 20% of polyvinylpyrrolidone (K30 manufactured by Nacalai Tesque) as the polymer II.
By weight, 100 parts by weight of distilled water was mixed and dissolved. This solution was transferred to a container lined with release paper and left at 60 ° C. for 20 hours to obtain a light yellow transparent sheet-like adhesive gel. When this gel was used to measure the AC impedance in the same manner as in Example 3, it was 71.5 kΩ.

[Comparative Example 4] 60 parts by weight of a 10% aqueous solution of polyacrylamide (manufactured by Wako Pure Chemical Industries) as Polymer I and polyvinylpyrrolidone as Polymer II (manufactured by Nacalai Tesque)
15 parts by weight of K30) was dissolved. This solution was transferred to a container lined with release paper and left at 60 ° C. for 40 hours to obtain a light yellow transparent sheet-like adhesive gel. Using this gel, the AC impedance was measured in the same manner as in Example 3 and found to be 182 kΩ.

In order to confirm the necessity of the N-substituted lactam as the hydrogen-donating amide group in the polymer II, the present inventors have confirmed that the other third amide group, N, N-dimethylamide group, Polymers having morpholyl amide groups were synthesized and the following experiments were conducted.

[Synthesis of poly (N, N-dimethylacrylamide)] N, N-dimethylacrylamide 30.2
g (0.305 mol) and 2,2′-azobis (2-cyanopropanol) 180 as a radical polymerization initiator
mg was dissolved in 250 ml of t-butanol, and polymerization was carried out with stirring under nitrogen atmosphere at 80 ° C. for 400 minutes. The obtained reaction liquid was dropped into 5 l of diethyl ether to precipitate a polymer, which was then separated by filtration. The obtained polymer was dissolved in methanol, filtered, and then reprecipitated with diethyl ether for purification.

[Synthesis of poly (acryloylmorpholine)] Acroylmorpholine 30.4 g (0.215 mol)
l), and 127 mg of 2,2'-azobis (2-cyanopropanol) as a radical polymerization initiator were dissolved in 250 ml of t-butanol, and the mixture was dissolved in a nitrogen atmosphere at 80 ° C at 40 ° C for 40 minutes.
Polymerization was carried out with stirring for 0 minutes. The obtained reaction solution is
While maintaining the high temperature, add dropwise to 5 l of diethyl ether,
After depositing the polymer, it was filtered off. The resulting polymer was dissolved in dimethylacetamide and filtered,
Purification was carried out by reprecipitation with diethyl ether.

[Comparative Example 5] As polymer I, 15 parts by weight of an ammonia-modified isobutylene-maleic anhydride alternating copolymer (Kuraray's Isoban IBM-110) and poly (N, N-dimethylacrylamide) previously synthesized were used. 31 parts by weight was dissolved in 100 parts by weight of distilled water. The obtained solution was put into a styrene petri dish and left at 60 ° C. for 16 hours, but it did not gel.

[Comparative Example 6] The procedure of Comparative Example 5 was repeated except that 15 parts by weight of poly (acryloylmorpholine) was used instead of poly (N, N-dimethylacrylamide). Similarly, it did not gel.

In order to confirm the necessity of the amide group in the polymer I, the present inventors conducted the following experiment using a sodium salt of isobutylene-maleic anhydride alternating copolymer.

[Comparative Example 7] 10 parts by weight of an isobutylene-maleic anhydride alternating copolymer (Kuraray Isoban IBM-10), 5.2 parts by weight of sodium hydroxide, and a polymer
Polyvinylpyrrolidone as II (K3 manufactured by BASF)
0) was dissolved in 40 parts by weight, and 17 g of sorbitol was dissolved in 100 parts by weight of distilled water. This aqueous solution was poured into a closed container lined with release paper and left at 60 ° C. for 16 hours, but it did not gel.

From the above results, the effect of the present invention is clear.

[0080]

As described in detail above, the medical conductive adhesive of the present invention has good adhesive strength and conductivity, and further has a shape-maintaining power after molding and a strong internal condensation power,
In addition, there are no problems such as skin irritation and cytotoxicity. In addition, it is cheap and economical. Therefore, when applied to various medical uses such as an electrocardiograph, an electroencephalograph, and an adhesive electrode of an electromyography, auxiliary means etc. are not required, and there is no adhesive residue after peeling. Also, because it has low skin irritation and high adhesive strength,
The measurement can be stably performed for a long time. Furthermore, since it is inexpensive, it can be suitably applied to disposable applications.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of an adhesive electrode to which a medical conductive adhesive of the present invention is applied.

[Explanation of symbols]

 10 Adhesive Electrode 12 Adhesive Conductive Layer 14 Backing Material 16 Electrode Projection

Front page continuation (72) Inventor Akira Mochizuki 1500 Inoguchi, Nakai-cho, Ashigarakami-gun, Kanagawa Terumo Corporation

Claims (1)

[Claims] Claims: (In the formula, R ¹ and R ² are —H or —CH
The _3, R ³ is -H, an alkyl group having 1 to 5 carbon atoms, or a phenyl group, Z is -COO ^- shows M ⁺ or -H, respectively. Note that M ⁺ represents any one of hydrogen ion, alkali metal ion, and ammonium ion. ), A conductive salt is added to an intermolecular hydrogen bond polymer complex consisting of a polymer I having a repeating unit having a hydrogen-donating amide group as a constituent and a polymer II having an N-substituted lactam. A medical conductive adhesive, characterized in that