JPH03254732A - Electric conductive adhesive pad - Google Patents

Abstract

PURPOSE:To speedily stabilize adhesiveness and waterproofness and permit easy handling by constituting the title pad from a crosslinking type water containing gel consisting of the acrylic acid methacrylic acid copolymer and/or the salt thereof, water and polyhydric alcohol, and a compound having at least two glycidyl groups in a molecule. CONSTITUTION:An adhesive pad is constituted of the crosslinking type water containing gel 3 consisting of the acrylic acid - methacrylic acid copolymer and/or the salt thereof, water and polyhydric alcohol, and a compound having at least two glycidyl groups in a molecule. Since the crosslinking of a gel body is carried out through chemical bonding in substitution for the metal bonding, the adhesiveness and waterproofness can be stabilized speedily, and the pad having the superior waterproofness and the high gel strength can be obtained, and the need of a net-shaped reinforcing member can be omitted. The manufacturing process can be simplified, and a plastic embossed tape 1 is charged with the pad, and crosslinking and hardening are generated, and the embossed tape 1 is covered with a top cover film 2, and products can be manufactured. Accordingly, easy handling is permitted, and also productivity is improved at a low cost.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is a conductive device for electrically connecting a bioelectrode of a conductor electrode used for low frequency treatment, electrocardiogram measurement, electroencephalogram measurement, etc., and medical examination to the skin on the surface of the human body. This invention relates to improvements in adhesive pads. [Prior Art] As shown in Fig. 3, a conventional conductive adhesive pad is made of a sheet-like body in which a conductive gel composition a is laminated with a net-like support sandwiched approximately in the center; It is commonly used to have a separator C such as a polyester film or a polypropylene film attached to the front and back surfaces of the body, and further to form ear-like extensions d of a net-like support for convenience in attachment and handling. The 5J electrolytic gel composition a contains polyacrylic M (hereinafter referred to as PAA) and/or polyacrylate (hereinafter referred to as FAA salt), polyhydric alcohol such as glycerin, sorbitol, propylene glycol, and water. karaari, Z
nO, MgO, Mg(OH)z, Ca(OH)zAl
(OH) 3+ AlCl5. Kali alum (KAI)
(504)!・Multivalent metal oxides such as 12H20),
Cross-linked hydrogels are used which are metal-bonded with polyvalent metal hydroxides or polyvalent metal salts (Japanese Patent Laid-Open No. 62-6351
2), that is, PA A (PA-COOH) is oxidized by polyvalent metal oxide or polyvalent metal hydroxide (i), (ii)
The reaction is as shown in the formula, FAA salt, e.g. PAA soda (p
a-coONa) reacts with a polyvalent metal salt, such as a metal sulfate salt, as shown in formula (iii). (i) 2PA-COOH+MgO→PA-COO-
Mg-00C-PA + HzO(ii) 3PA-
COOH+ AI(OR) s→P^-Coo-AI-
00C-PA+2PA-COO←ゝ+311.0(ii
i) 6PA-COONa +AIz(SO4)i
=2PA-COO-AI-00C-PA +2P
^-COO←' 3NazSOa Also, since the above polyhydric alcohol functions to prevent water evaporation, it is used here as a water retention agent. [Problems to be solved by the invention] Such conventional conductive adhesive The pad consists of a carboxylic acid or carboxylate salt of a pace polymer side chain and an oxidized polyvalent metal;
It takes a very long time for the metal bond with the polyvalent metal hydroxide or polyvalent metal salt to become uniform within the gel system, and it takes more than a week for the tackiness to stabilize (the tackiness is initially high and gradually decreases. ), it takes more than two months for water resistance to stabilize (water resistance is initially low and increases gradually), and because the bonding group ionizes with water, it becomes slimy if used when sweating heavily. If the gel is immersed in water for more than a day, it will dissolve.Also, since the pace polymer is made of PAA and/or FAA salts, which have low mechanical strength, it is difficult to handle the gel alone in a sheet form. / There are inconveniences such as the need to incorporate a tab-shaped support for reinforcement, and although it has been put into practical use, there are still problems. The present invention easily eliminates these conventional drawbacks, quickly stabilizes the adhesiveness and water resistance of the adhesive pad, has high gel strength, and can be easily handled in sheet form, making it useful for product production and commercial use. The object of the present invention is to easily provide an inexpensive conductive adhesive pad that is free from inconvenience in handling. [Means for Solving the Problems] The present invention provides a conductive adhesive pad made of acrylic acid-methacrylic acid copolymer (hereinafter referred to as AAMAA) and/or acrylic acid-methacrylic acid copolymer (hereinafter referred to as AAMAA).
It is characterized by being composed of a crosslinked hydrogel containing as essential components a methacrylic acid copolymer salt (hereinafter referred to as AAMAA salt), ice, a polyhydric alcohol, and a compound having at least two glycidyl groups in the molecule. It is an ILN adhesive pad. In this case, the AAMAA is CH8~(CH2Cl), -(CIhC). ~---・(i
v-1) It is a random copolymer of C00II C00N represented by (iv 1) 2, and when it is neutralized with NaOH, it becomes A shown by the formula (iv-2).
It becomes AMAA salt. CH. ~(CHzCH)-(CHzC), ~・= (i
v-2) COONa COONa These are polymer electrolytes like FAA and FAA salts, and in the presence of water, polyvalent polymer ions (polyII
er) -Coo←) and a large number of low-molecular-weight ions H+-, and can exhibit electrical conductivity of approximately 10"4Ω・α due to ionic conduction. In addition, AAMAA has a glass transition point similar to that of PAA at 100°C (
FAA salt has a temperature of 185'C (AAMA
Salt A has a high temperature (185℃ or higher), has a methyl group on the opposite side of the carboxyl group in the methylene chain, and has a bulkier structure than FAA, making it difficult for molecular movement to occur, so it has excellent strength. The sheet-like gel body can be easily handled. According to the invention, said AAMAA and/or AAMAA
Three-dimensional cross-linking of salts creates chemical bonds, namely epoxy bonds (po
lya+er)-C00C)1gCI((OH)CHz
-CHzC)l(OH)C)lzOOC-(polym
er), three-dimensional crosslinking within the system proceeds rapidly, stabilizing the adhesiveness and water resistance in a short time, and also making it possible to obtain high water resistance. Examples of the compound having at least two glycidyl groups in the molecule of the present invention include CHJ-EP CH20-EPC having the chemical structural formula shown below.
HO-H(or-EP) CHsCHz
CC1(z04(or-EP)CHJ~EP
C11zO-EP [1] [2] CH2 1 EP-OCHz CCHzO-EPH3 [3] EP-0 (CHi) 60-EP EP-0 (CIIC1l!O), -EP [4] [5] CI (3 EP -0(CHCHzO)--EP EPJ(C1'1tGHzCHzO)--EP [6] [7] EP-0-(CHzCHCHzOCHzCHCHzO)
, EpH 0H0-EP [10] EP-OCR. CH,0-EP EP-OCR. cogo-Ep CToCH*0-EP ■. . /\. . 0-EP 0-EP llOH CH! 0-EP [12] 0 EP-OCO-CHzCHzCHzCHz-Coo-E
P [14] Glycerol polyglycidyl ether [l]. Trimethylolpropane polyglycidyl ether [2
], Neopentyl glycol diglycidyl ether (
3), 1.6-hexanediol diglycidyl ether [4], ethylene & polyethylene glycol diglycidyl ether [5], propylene and polypropylene glycol diglycidyl ether [6], polytetramethylene glycol diglycidyl ether [6] 7],
Sorbitol polyglycidyl ether (8), 1.4
-Sorbitan diglycidyl ether

[9] Diglycerol & polyglycerol polyglycidyl ether (
10), pentaerythritol polyglycidyl ether (11), glycidyl tris(2-hydroxyethyl) isocyanurate (12), resorcinol diglycidyl ether [13], and other glycidyl tail compounds and adipic acid diglycidyl ester ( 14)
, O-phthalic acid diglycidyl ester [15] and other glycidyl ester compounds. These compounds having two or more glycidyl groups may be used alone or in combination of two or more types. In these chemical structural formulas, -EP represents a glycidyl group -CHlCHCHz. \I Also, for the formation of the three-dimensional crosslink, a compound having at least two isocyanate groups in the molecule is used, that is, a urethane bond (polymer) -COOCONH--
A compound based on NHOCOOOC-(poly+5et) is also optional, and such compounds include 2.4-toluylene diisocyanate (2,4-TDI), 2.
6-TDI, 4.4'-diphenylmethane diisocyanate (MDI), 4.4'-dicyclohexylmethane diisocyanate (H+JDI). Isophorone diisocyanate (IPDI), hexathymethylene diisocyanate (CHDI), 1.5-naphthalene diisocyanate (XDI), )lysine diisocyanate (TODI), 1.4-phenylene diisocyanate, xylylene diisocyanate (XDI),
Hydrogenated X[lI (H,XDI). Lysine diisocyanate, triphenylmethane triisocyanate + @-&P-tetramethylxylene diisocyanate (s+-&p-TMXDI), lysine ester triisocyanate, 1,8-diisocyanate 4
Isocyanate methyl octane, 1.3.6-hexamethylene triisocyanate 2.2.4-trimethylhexamethylene diisocyanate (2,2,4-TMDI
). 2.4. In addition to diisocyanates and triisocyanates such as 4-TMDI, these are trimethylolpropane. Examples include the use of polyisocyanates such as 2,4-TDI-)limethylolpropane adducts stabilized by addition to pentaerythritol, sorbitol, methyl glucodite, sucrose, and the like. Polyhydric alcohols used in the present invention include glycerin, polyglycerin, sorbitol, ethylene glycol, diethylene glycol, polyethylene glycol,
Propylene glycol Conventionally used propylene glycol such as dipropylene glycol, polypropylene glycol, and ethylene-propylene gelicol copolymer may be used. The gel composition of the present invention can be prepared, for example, by dispersing AAMAA in a polyhydric alcohol, adding a small amount of the above-mentioned compound having a glycidyl group or isocyanate group, and stirring to form a sludge.
Adjust the pH to 1 using a neutralizing agent such as aOH, and finally add water and stir to form a viscous polymer liquid. Note that it is optional to add FAA or FAA salt as necessary. Since the viscosity of this polymeric viscous liquid can be controlled to about 1 million cP, it can be metered and dispensed using a Mono Pump 1 (rotating displacement type - eccentric shaft screw pump) type dispenser, and it can be dispensed into sheets using the following method. In other words, as shown in Fig. 1, the polymer viscous liquid is poured into the recesses of a plastic empost tape 1 in which recesses of a predetermined shape are continuously formed at regular intervals. A cross-linked water-containing adhesive pad is obtained by applying a predetermined temperature for a predetermined period of time.The surface is then covered with a top cover film 2 to seal the periphery of the recess, and the outer edge of the sealed portion is punched out to form a product. The end user can use it by peeling off the top cover film 2 from the plastic quench post tape l, attaching the adhesive pad to the bioelectrode, and peeling the plastic quench post tape from the adhesive pad. Plastic empost tape has a thickness of 0.2 to 0.
．． 6m polyvinyl chloride tape, polystyrene tape,
Selected from polypropylene tape, polycarbonate tape, polyester tape, polyarylate tape, etc. In addition, the top cover film is made of polyester film, polyolefin film, etc. with a thickness of 10 to 50 μm, and is made of copolymerized polyester, styrene-butadiene-styrene copolymer, ethylene-vinyl acetate copolymer, etc. with a thickness of 2 to 20 μm. It is preferable to use one provided with a heat-sealing adhesive layer, and in order to automate the filling process, crosslinking process, heat sealing process, punching process, etc.
As shown in the figure, it is preferable to carry out assembly work while transporting a plastic Empost tape with sprocket holes continuously arranged at regular intervals on both ends. (Example 1) (A) AAMAA "Jurimar J AC-2OL" (manufactured by Nippon Pure Chemical Industries, Ltd., trade name) with a molecular weight of so and ooo as measured by GPC (gel permeation chromatography)
Disperse 100 fE of AAMAA salt in 300 parts by weight of glycerin, and add 10 parts by weight of glycerol dicrycidyl ether "Bunacol" EX-313 (manufactured by Nagase Kakai Kogyo ■, trade name) as a crosslinking agent. After stirring, dissolve in 400 parts by weight of tap water and stir to obtain +11)1 about 3. A viscous polymeric liquid (A) having a viscosity of approximately 750.0 OOcPO was prepared. CB) Next, the molecular weight by GPC measurement is so, ooo ~
100.000 AAMAA, r Jurimar JAC20
100 parts by weight of H (manufactured by Nippon Pure Chemical Industries, Ltd., trade name) and 250 M parts of propene gellicol were dissolved in 500 parts by weight of tap water, and then 40 parts by weight of NaOH was added to perform 70% partial neutralization. Next, ethylene glycol diglycidyl ether, "Bunacol JEX" was added to this solution as a crosslinking agent.
Add and stir 5 parts by weight of 810 (manufactured by Nagase Kaei Kogyo ■, trade name) and 150 parts by weight of tap water to prepare a viscous polymer liquid (B) with a pH of about 6.5° and a viscosity of about 1,000.0OOcPO. did. (C) For comparison, the molecular weight measured by GPC is 1.00.
FAA of 0,000 to 2,000,000, r Julimar-J AC-10H (manufactured by Nippon Pure Chemical Industries, Ltd., Minami product name) 100
parts by weight and 400 parts by weight of glycerin were dissolved in 500 parts by weight of tap water, and 40 parts by weight of NaOH was added to give a solution of 70%.
After partial neutralization, 10% crosslinking agent was added to this solution.
Add 150 parts by weight of potash alum and adjust the pH to about 6.5. Viscosity approximately 1,500,000 cPO polymer viscous liquid (C)
was prepared. On the other hand, a hard polyvinyl chloride tape with a thickness of 0.4 mm and a width of 60 mm and a length of 500 nm, 5P710G (Shin-Etsu Polymer ■
(manufactured by Shin-Etsu Polymer ■) and carrier tape bottom type II (manufactured by Shin-Etsu Polymer ■) to a depth of 2.5 mm as shown in Figure 1.2. O
wm, flat-bottom unevenness processing with a width and length of 40m (R5m at the four corners) was performed at a pitch of 50m, and sprocket holes with a diameter of 2 were drilled at a pitch of 5 at a distance of 2.5m from both ends of the tape using a progressive die. , a plastic embossed table 1 was prepared. Next, the polymer viscous liquids (A), CB>, and <c> were placed in the recesses of separate plastic embossed tables 1 using a dispenser with a discharge amount of 14 to 140 cj and a discharge accuracy of ±0.08-; Heishin Monoro Body Spencer 3NDPO
Using 6-D (manufactured by Heishin Gizai ■, trade name), fill the cough recess so as to almost fill it (A). A top cover film, 5P-5 (manufactured by Shin-Etsu Polymer ■, trade name), was prepared by separately preparing a polyester film with a thickness of 38 μm and a heat-sealable adhesive layer with a thickness of 5 μm. This surface was covered, the peripheral edge of the recess was heat-sealed, and the outer shape was punched out. For evaluation of electrical performance and adhesive strength, this top cover film was peeled off and the conductive adhesive pad (A) was used. (BL (C) When the surface resistance of (A), (B) and (C) were both 5 to IOMΩ/mouth, there was no significant difference. When it was attached to the conductor electrode of (name) and attached to the inventor's shoulder and used at DC6VX40Hz, (A)
, (B), and (C) all worked without problems, and it was confirmed that they had the same performance as the adhesive pad attached to MH-103 and MH-10 (manufactured by Sharp ■, trade name). Mechanical strength was evaluated using conductive adhesive pads (A) and (B) from the recesses of the plastic embossed tape. When I tried to take out (C) with my fingertips, (A) appeared. (B) was able to be picked out in sheet form, but (C)
The shape could not be preserved and it could not be removed. Also, rubber hardness needle (JI
When the hardness of the adhesive body was measured using (S-A type), it was found that (C
) is so soft that the pointer does not move even slightly, but (A), (
B) was approximately 5@Hs. The water resistance evaluation was as follows: ■ Conductive adhesive material after weeks (A);
When (B) and (C) were immersed in water for 24 hours, (C
) has completely melted, but <A>. Although (B) swelled, it almost retained its shape. [Effects of the Invention] The present invention provides an acrylic acid-methacrylic acid copolymer and/or an acrylic acid-methacrylic acid copolymer salt, water and a polyhydric alcohol, and a compound having at least two glycidyl groups in the molecule. By constructing the adhesive pad from a cross-linked hydrous gel, the cross-linking of the gel body is performed by chemical bonds instead of metal bonds, so the adhesive properties and water resistance are quickly stabilized, and the adhesive has excellent water resistance. Since the pad can be made into a conductive adhesive pad with high gel strength, it is possible to omit the Bennett-like reinforcing material compared to conventional ones, simplifying the manufacturing process, and also making it possible to use plastic embossed tape. It is possible to commercialize the product by filling it in a container, cross-linking and curing it, and covering it with a top cover film, which is easy to handle, greatly improves productivity, and can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the conductive adhesive pad of the present invention, in which the concave portion of a plastic embossed tape is filled with a cross-linked hydrogel, Fig. 2 is a plan view thereof, and Fig. 3 (A) (B). )
1 is a vertical cross-sectional view and a plan view of a conventional adhesive pad. DESCRIPTION OF SYMBOLS 1...Plastic embossed tape, 2...Tomb cover film, 3...Crosslinked hydrogel, 4...
Sprocket hole, 5... punching break line.

Claims (1)

[Claims] (1) A cross-linked water-containing compound consisting of an acrylic acid-methacrylic acid copolymer and/or an acrylic acid-methacrylic acid copolymer salt, water, a polyhydric alcohol, and a compound having at least two glycidyl groups in the molecule. A conductive adhesive pad characterized in that the adhesive pad is made of gel.