JPS5980925A - Rubber plug for electrolytic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber stopper for an electrolytic capacitor, and more specifically, it is used to seal electrolyte that may leak from around lead wires extending outside from a capacitor element and around the inner edge of a case. It is something.

For the sealing of electrolytic capacitors, natural rubber, 5BR1, or a resin (phenolic resin or polypropylene resin plate) pasted to the above-mentioned rubber has been used. Penetration, swelling and permeation of rubber resins by liquids, rubber-containing substances (halides, sulfur compounds, etc.) against exterior materials (aluminum, zinc, resins) and heavy substances (aluminum, tin, zinc, silicone, titanium, tantalum) The electrolyte corrodes, causing loss in the capacitor (the main measurement item, ton δ).In addition, many types of electrolytes have recently been developed due to demands for explosion-proof properties, anti-corrosive tactility, durability, flame retardance, heat-resistant stability, etc. Although they are used in combination, the main ones are insulating oil, paraffin, wax, barium titanate, titanium oxide, aluminum oxide, tantalum oxide,
Chlorinated biphenyls, ammonium borate, manganese nitrate, lithium chloride, ethylene glycols (diethylene glycol, butyl carpitol, etc.), mancan nitrate, acid amides, strong acids, tricresyl phosphinyl 1~,
There are orthophosphoric acid esters, acid amides (dimethylformamide, adipic acid amide, phthalofluoric acid esters, diphenyl ethers, higher resin ammonium, alkylbenzenes, etc.), and these chemicals penetrate, swell, and permeate rubber and resin. This causes liquid leakage and loss in the capacitor (main measurement item ton δ).Therefore, due to aging, it is necessary to replace the capacitor with a new one after several years.

As countermeasures against aging, research on new materials, mixing methods of known materials, cross-linking of materials, etc. has been conducted, but these efforts have only increased the product price and have not resulted in good products.

However, as a result of intensive research, the inventor determined that the blending ratio of EPM, EPDM, or IIR was 20 to 60% by weight of other compounding agents, and the crosslinking density by the crosslinking agent was 0.5 to 100 m01/CC.
×10-4 cross-linked plug body, and in parallel with the cross-linking molding of the plug body, at least the surface portion of the plug body that comes into contact with the electrolyte is laminated in an integrally bonded manner. As an encapsulating body for electrolytic capacitors, it is inexpensive and does not change over time due to its airtightness, liquid leakage resistance, aging resistance, corrosion resistance, durability, resistance to penetration by electrolytes and cleaning solvents, and swelling penetration. It is.

Therefore, various types of radio, television, stereo audio equipment, computer photography equipment, electronic equipment, wired and wireless communication equipment, measuring instruments, industrial instruments, etc. that use the electrolytic capacitor equipped with the rubber stopper of the present invention, etc. industrial equipment,
It is extremely useful for vehicles, space satellites, aircraft, ships, etc. because of its enhanced safety.

Next, the constituent materials of the rubber stopper (A>) of the present invention will be explained in detail.

EPM is a double bond-free rubber bridged by organic peroxides. EPDM has a double bond in the third component, sulfur,
Can be crosslinked using organic donor vulcanizing agents, phenolic resins, organic peroxides, etc.

Although 11R causes depolymerization with organic peroxides, there is also IIR modified with divinylbenzene so that it can be crosslinked.

These rubbers have slightly different crosslinking methods, but the common properties are that they are polymerized in solution, and are aging resistant and generally difficult to crosslink. The crosslinking agents used to crosslink this rubber include sulfur, tetraethylthiuram disulfide (TE
TD), tetraethylthiuram disulfide (T
(abbreviated as MTD), dipentamethylene thiuram tetrasulfide (abbreviated as DPTT), 4,4' dithiodimorpholine (abbreviated as DTDM), P,P' dibenzoylquinone dioxium (abbreviated as DBQDO), dicumyl peroxide (abbreviated as DBQDO) (abbreviated as DQPO), P-quinone dioxiram (QO
), 1,1-di-t-butylperoxy, 3,3
．． 5-trimethylcyclohexane, 2,5-dimethyl-
2,5-di(t-butylperoxy)hexane, sheet
-7-tyl peroxide, α, α°-bis(t-butylperoquine)-P-diisopropylbenzene (B-BPO
DIPB), γ-glycid, oxypropyltrimethoxysilane, γ-methacrylooxypropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane (AEAPTMSi) di- or polymeric Crosslinking promoters include mixtures of thiol phenols, zinc oxide, magnesium oxide, lead peroxide, dibenzothiazyl disulfide (abbreviated as MBTS), 1,2-polybutadiene (abbreviated as PBG), triallyl cyanurate (abbreviated as MBTS), etc. (abbreviated as TAG) metal salts and esters of methacrylic acid and acrylic acid stearic acid N,N'-
Metaphenylene dimerinsite, etc.

These crosslinking agents and crosslinking accelerators may be used alone, or several types may be used in combination.

In this case, other types of crosslinking agents have greatly different efficacies, and when used in combination, they may exhibit a synergistic effect, but conversely, they may not exhibit crosslinking properties at all. Just like crosslinking agents, crosslinking accelerators have positive and negative crosslinking effects. Therefore, EPM that is difficult to cross-link by combining a cross-linking agent and a cross-linking accelerator;
[PDMl and IIR, crosslinking density (0,5-100
io1/cc) x 10-'k: This is an important factor in making the cross-linked N-solution capacitor a sealed product. In addition, it is suitable for the crosslinking density to be within the above-mentioned range in terms of sealability; if the crosslinking density is less than this value, the deformation strain becomes large and long-term sealability is lost.

Conversely, if it is larger than the stated value, the elastic modulus will be 1 to 3
It becomes hard as 10 dyne/cm2, deforms greatly at high and low temperatures, and loses its sealing properties.

Note that the rubber compound filler is an element that affects thermal deformation.

This filler includes clays, mica, talc, quartz, silicon oxide, limestone, heavy calcium carbonate, surface treatment, calcium carbonate, magnesium carbonate, carbon black, and the filling resin includes phenol, melamine, urea, ethylene vinyl acetate, Examples include unsaturated Nisdel and acrylic resins.

No, rubber processing aids, plasticizers, pigments, etc. are mixed with rubber to form the constituent material of the plug body (1), but the amount of rubber compounded is 20
A content of up to 60% by weight, preferably 30 to 50% by weight, is suitable for sealing an electrolytic capacitor.

The material of the fluororesin layer (2) that is laminated on the surface or the entire surface of the stopper body (1) includes a copolymer of tetrafluoroethylene and ethylene (abbreviated as ETFE), tetrafluoroethylene and hexafluoropropylene. Copolymers of tetrafluoroethylene and perfluoroalumaxyethylene (abbreviated as FEP), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (abbreviated as PFA), tetrafluoroethylene resins (abbreviated as PFA)
PTFE), chlorotrifluoroethylene resin (
(abbreviated as PCTFE), polyvinylidene resin (PVD)
There are homopolymers such as

These resins are about 7 to 1 times cheaper than IIR, EPDM.
It is 0 times more expensive, and the glass transition point of FEP is as high as about 210°C. (The glass transition point of EPM, EPDM, and 11R is about -50 to -65°C.) Therefore, if the encapsulation of an electrolytic capacitor is formed only from fluororesin and used, the sealing performance against temperature changes will deteriorate. Also, fluororesin MP
.

Even if EPDM and IIR are mixed, they cannot be mixed uniformly, and furthermore, they cannot be co-crosslinked. Therefore, a hard product with good sealing performance cannot be obtained. Furthermore, EPM,
If the rubber surface of EPDM and IIR is simply laminated with resin, the adhesion between the rubber and resin layer will be poor and air bubbles will form.

For this purpose, the resin surface is specially treated and the plug body (
Peeling force is 0.5 kg/cm when bonded at the same time as 1) crosslinking.
That's all. This surface treatment technology includes corona discharge, glow discharge, and arc discharge plasma treatment. This treatment involves attaching electrons, atoms, ions, radicals, etc. to the resin surface. In this case, vacuum, nitrogen, ammonia , oxygen, or helium, the resin will have a sputtering effect and the peeling force will increase.

Other resin surface treatment methods include a primer method in which a mixed agent of a silane coupling agent, sodium, naphthalene, and hydrofuran is applied.

Fluororesin is a rubber stopper (1) that has rubber elasticity and chemical and solvent resistance by laminating the entire surface of the stopper body (1) with a resin that can withstand high temperatures and long periods of time against all electrolytes. A) can be made. In addition, in order to reduce the product price, fluororesin is laminated only on the surface exposed on the inside of the capacitor to make the outside air contact surface a rubber surface, or the outside air contact surface is laminated with polysalvon, polyarylate, polyethylene, A layer of resin such as vinyl chloride may also be laminated. Since adhesion of such resins is easier than that of fluorine resins, films of polybutylene terephthalate, polyamide, and vinylidene chloride are laminated without treatment to form a rubber stopper.

These resins also contain trichloroethane, trichlorethane [1]
Since it is resistant to solvents such as ethylene, brazing wax from electrolytic capacitors may be used as the removal agent.

Next, the procedure for molding the rubber stopper (Δ) will be briefly described.

(2) The surface of the fluororesin film is subjected to plasma treatment or Blurmer treatment.

(2) When laminating the outside air contact surface of the stopper body (1), perform plasma treatment or primer treatment appropriate for the type of resin.

■The rubber compounding amount of EPM or EPDM or IIR is 20
Other ingredients such as fillers, softeners, and processing aids are added so that the amount is ~60% by weight, and a crosslinking agent is added so that the crosslinking density is 0.5~100mol/ccx 1Q-4. The crosslinking accelerator is appropriately selected from many types. Rubber compounding is performed by mixing using two rolls or an internal mixer to uniformly disperse the compounding ingredients, and then dispensing to a constant thickness.

■Place the fluororesin ■ on top of the crosslinking mold, and place ■ on top of it.
A compound rubber of 0.5 is placed, and in some cases, a resin of
A rubber stopper (A) consisting of a stopper body (1) with a crosslinking density of ~100 mol/ccx 10- is molded.

■Wash with solvent and water if necessary.

Next, examples will be shown.

Example 1: Fluororesin surface-treated ETFE film (Mitsui 70 Rochemical Industries Co., Ltd. with a thickness of 0.
Primer treatment is performed on one side of 13+nm Chemlock 607 (Lord Far East Inc.).

■, Blend Example 1 of the stopper body 1IR (JSRButy1218=Japanese Synthetic Rubber>
100 parts zinc oxide (#1 = Mitsui Kinzoku Kogyo)
5 parts stearic acid = Kao Soap) 1 part QO (Actor-Q = Kawayo Chemical Industry)
5th part MBTS (Accel DM = Yoro Kagaku Kogyo Co., Ltd.)
8 parts lead oxide (= Nihon Kagaku Kogyo)
10 parts L/-(Di
xie=Vanderbilt)
80 parts paraffin = Nippon Oil
10 parts Carbon black (G-ST-Tokai Carbon> 50 parts Example 2 EPDM (Mitsui EPT4045 = Mitsui Petrochemical Industries)
100 parts zinc oxide (#=Mitsui Kinzoku Kogyo)
5 parts stearic acid (= Kao soap) 1 part BBPODIP
B (Barriki Dox 14 = Kayaku Nouri) 1.8 parts TAC (TAIC-Nippon Kasei)
1.8 parts carbon black (Geast 3 = Tokai Carbon) 50 parts talc (Mistron)
Vapor=8ierra>
100 copies Example 3 EPDM (JSREP65=Japan Synthetic Rubber)
100 parts zinc oxide (#1 = Mitsui Kinzoku Kogyo)
5 parts stearic acid (-Hanadama soap) 1 part DTDM (Parnock R = Ouchi Shinko Chemical) 2 parts DPTT (Tsukusera TRA = Ouchi Shinko Chemical) 1 part MB'r
S (Accel DM=Uro Kagaku Kogyo)
25 parts Surface treated calcium carbonate (white ene soda = Shiroishi Kogyo)
50 copies mica (= Shiroishi Kogyo)
50 parts Magnesium carbonate (-Tokuyama Nda)
30 parts triethanolamine (=Mitsui Toatsu Chemical) 2 parts Example 4 EPM (JSREP-11=Niki Synthetic Rubber)
100 parts zinc oxide (#1 = Mitsui Kinzoku Kogyo)
5 parts stearic acid (= Kao soap) 1 part 1
．． 2 Polybutadiene (= Nippon Soda)
2 parts dibenzoylquinone dioxime (Parnock DGM = Ouchi Shinko Chemical) 1 part 2,5-dimethyl-2
,5-di(t-butylperoxine)hexine (perhexine 2.5+3=NOF>
1.5 parts) J-bon black (Geest = Tokai Carbon> 20 parts T-dylene vinyl acetate (Ultrasen 630-Toyo Soda Kogyo) 20 parts unsaturated polyester resin (2063 = Sumitomo Chemical)
30 parts mica (-Shiraishi Kogyo)
50 parts Comparative Example 1 Natural rubber (R8SNo, 1>
100 parts zinc oxide (#1-Mitsui Kinzoku Kogyo)
5 parts stearic acid (-Kao Soap) 1 part sulfur (colloidal sulfur = Hosoi Chemical)
25 parts MBTS (Accel DM = Yoro Kagaku Kogyo)
1 part diphenylguanidine (Accel D = Yoro Kagaku Kogyo) 1 part Shincal (-Shiraishi Kogyo) 20
Part 2.2.4-trimethyl-1,2-dihydroquinoline condensate (Antage RD-Ro Kagaku Kogyo)
1.5 parts carbon black (Jeast 3=
Tokai Carbon) 5 parts or more is SRI
Vulcanization test Vulcanization mold (JISC5113-CQ922M2A683
A surface-treated Teflon FEP (w = 18 H: 14 T near) was placed, a compounded rubber was placed thereon, and molding and crosslinking was performed under the vulcanization conditions listed in the table.

Example 1 Example 2 Example 3 Example 3 Example 4
Comparative example 1 Comparative example 22 Gono, minute (%) 37.7 38.5 40.0
110,9 43,4 73 7
3xlO') Φ) Peeling force: A peeling test between the fluororesin layer (2) and the plug body (1) is conducted in accordance with ISK [vulcanized rubber physical testing method].

Crosslinking density = Test method “Rubber test method” (Japan Rubber Association, published in 1980, P.
Flory-Rehn
Quote 1 Calculate the er formula.

Sealing degree - Accurately weigh 2g of calcium chloride, put it in a bottle, and measure the thickness.
5 + nm 1 diameter 20111111 A cylindrical rubber stopper (A>) is covered and left in a constant temperature and humidity chamber with 100% humidity and a temperature of 80°C, and the water absorption of calcium chloride is measured using Karl Fischer reagent.

Compression set = J l5K6031 [Vulcanized rubber physical test method].

The crosslinking temperature and crosslinking time were adjusted to suit the sealing of electrolytic capacitors, as shown in the table showing the test results of rubber compounding amount and crosslinking density. Among them, in Example 3-2, since the crosslinking temperature was lowered, the crosslinking density was also lowered, resulting in poor sealing performance. Note that the compression set also increases.

A comparison was made with respect to natural rubber in Comparative Examples 1 and 2, but
Although the peeling force is high, the compression set is also large and the sealing performance is poor.

Although not listed in the table, the ETFE film surface is not treated,
If the compounded rubber is placed as is and cross-linked, the peeling force will be O.
, '1 to 0.2 kg/c+++, which is inferior.

In the above example, tests were conducted on a laminated product with only one side of the stopper body (1), but products with a resin layer (3) such as polyethylene on the entire surface or the surface in contact with the outside air can also be manufactured using the same process. obtain.

[Brief explanation of drawings]

1 to 3 are sectional views showing electrolytic capacitors sealed with rubber plugs according to embodiments of the present invention. In the figure, A shows the rubber stopper 1, and the stopper body 2 shows the fluororesin layer. ? Author: December q, 1981 Kazuo Wakasugi, Commissioner of the Patent Office (Examiner of the Patent Office) 1. Indication of the case Patent Application No. 192312 of 1987 2. Name of the invention Rubber plug for electrolytic capacitor 3. Amendment Relationship with cases involving persons who apply for patents Patent application Name: Toritsu Kogyo 4, Agent address: 5-14-7 Hakusan, Bunkyo-ku, Tokyo Showa
6. Amendment subject to amendment Description 1, Name of the invention Rubber plug for electrolytic capacitors 2, Claims ■ Ethylene propylene □, rubber or ethylene propylene terpolymer or butyl rubber in a different blending ratio 20 to 60% by weight of the compounding agent and a crosslinking density of 0.5 to 100
A plug body cross-linked to mol/ccx 10-4;
A rubber plug for an electrolytic capacitor comprising a fluororesin layer integrally laminated on at least a surface portion of the plug body that comes into contact with an electrolytic solution in parallel with cross-linking molding of the plug body. A rubber plug for an electrolytic capacitor according to claim 1, wherein the fluororesin layer is laminated over the entire surface of the plug body. (2) The rubber plug for an electrolytic condenser according to claim 1, wherein the fluororesin layer is laminated on a surface portion of the plug body that comes into contact with the electrolyte, and the remaining surface portion is laminated with another synthetic resin layer. (2) The rubber plug for an electrolytic capacitor according to claim 1, 2, or 3, wherein the fluororesin layer is plasma-treated at the surface where it joins with the plug body. ■ Claim 1 or 2, wherein the fluororesin layer is treated with a primer on the joint surface with the plug body.
Rubber plug for an electrolytic capacitor according to item 1 or 3. 3. Detailed Description of the Invention The present invention relates to a rubber stopper for an electrolytic capacitor, and more specifically, it is used to seal electrolyte that may leak from around the lead wire extending outside from the capacitor element and around the inner edge of the case. be. For sealing electrolytic capacitors, natural rubber, 5BR1, or a resin (phenol resin or polypropylene resin plate) bonded to the above-mentioned rubber has been used. These are caused by aging of rubber due to heat and oxygen, penetration, swelling and permeation of rubber resin by electrolyte, and exterior materials (aluminum, zinc, resin) and electrical materials (aluminum, zinc, resin) due to rubber containing substances (halides, sulfur compounds, etc.). It corrodes aluminum, tin, zinc, silicon, titanium, and tantalum, causing capacitor loss (main measurement item ton δ).Also, the electrolyte has explosion-proof properties, corrosion-preservative tactility, durability, flame retardancy, Due to the demand for heat resistance and stability, many kinds of materials have recently been used in combination, but the main ones are insulating oil, paraffin, wax, barium titanate, titanium oxide, aluminum oxide, tantalum oxide,
Biphenyls chloride, ammonium borate, manganese nitrate, lithium chloride, ethylene glycols (diedlene glycol, butylcarpitol, etc.), mancan nitrate, acid amides, strong acid, tricresyl phosphinyl 1~,
There are orthophosphoric acid esters, acid amides (dimethylformamide, adipic acid amide, phthalofluoric acid esters, diphenyl ethers, higher resin ammonium, alkylbenzenes, etc.), and these chemicals penetrate, swell, and permeate rubber and resin. This causes liquid leakage, which causes capacitor loss (the main measurement item is toll δ). Therefore, due to aging, it is necessary to replace the capacitor with a new one after several years. As a countermeasure against aging, research on new materials and mixing of known materials are being carried out. Although research has been conducted on cross-linking of materials and materials, it only increases the product price and no good product has been obtained yet.However, as a result of intensive research, the inventor found that the mixing ratio of EPM, EPDM, or IIR to 20 to 60% by weight of other compounding agents, and the crosslinking density by the crosslinking agent to 0.5 to 100 mol/
Consisting of a plug body cross-linked to Q-4, and a fluororesin laminated integrally with at least the surface portion of the plug body that comes into contact with the electrolyte in parallel with the cross-linking molding of the plug body. As a sealing body for electrolytic capacitors, we have obtained an inexpensive seal that has excellent airtightness, resistance to liquid leakage, aging resistance, corrosion resistance, durability, resistance to electrolytic solution and cleaning solvent penetration, swelling permeation, and does not change over time. It is something that Therefore, radios, televisions, stereo sound equipment, computers, photographic machines, electronic equipment, wired and wireless communication equipment including electronic circuits, measuring instruments, industrial instruments, etc., which employ the electrolytic capacitor equipped with the rubber stopper of the present invention, It is extremely useful for various industrial equipment, vehicles, space satellites, aircraft, ships, etc. because of its enhanced safety. Next, the constituent rope materials of the rubber plug <A) of the present invention will be explained in detail. El)M is a double bond-free rubber crosslinked with organic peroxides. EPDM has a double bond in the third component and can be crosslinked with sulfur, an organic donor vulcanizing agent, a phenolic resin, an organic peroxide, or the like. 11R causes depolymerization when used with organic peroxides, but there is also IIR modified with divinylbenzene to enable crosslinking. These rubbers have slightly different crosslinking methods, but the common properties are that they are polymerized in solution, and are aging resistant and generally difficult to crosslink. The crosslinking agents used to crosslink this rubber include sulfur, tetraethylthiuram disulfide (T
4.4
'Dithiodimorpholine (abbreviated as D T D' M), P
, P' dibenzoylquinone dioxium (abbreviated as DBQDO), dicumyl peroxide (abbreviated as DQPO), P
-quinonedioxiram (abbreviated as QO), 1.1-di-t
-butylperoxy, 3,3.5-1-limethylcyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylperoxide,
α,α′-bis([-butylperoquine)-P-diisopropylbenzene (abbreviated as B-BPODIPB), γ-
Glycid, oxypropyltrimethoxysilane, γ-methacrylooxypropyltrimethoxysilane, N-β
(aminoethyl)-γ-aminobutylene-oxysilane (abbreviated as AEAPTMSi) di- or polymethylphenol mixtures, and the like. In addition, the crosslinking accelerators include zinc oxide, magnesium oxide, peracid, dibenzothiazyl disulfide (abbreviated as MBTS), 1,2-polybutadiene (abbreviated as PBG), triallyl cyanurate (abbreviated as TAC), methacrylic acid. and metal salts and esters of acrylic acid stearic acid N, N'
-Metaphenylene dimerinate, etc. These crosslinking agents and crosslinking accelerators may be used alone, or several types may be used in combination. In this case, other types of crosslinking agents have greatly different efficacies, and when used in combination, they may exhibit a synergistic effect, but conversely, they may not exhibit crosslinking properties at all. Just like crosslinking agents, crosslinking accelerators have positive and negative crosslinking effects. Therefore, by combining a crosslinking agent and a crosslinking accelerator, crosslinking becomes difficult.
, EPDM, and IIR with a crosslinking density of 0.5 to 100
mol/ccx 1 Crosslinking to Q-4 is important for sealing products of electrolytic capacitors. Also, it is suitable that the crosslinking density is between the sealing property and the above-mentioned value, and if the crosslinking density is less than this value, the deformation strain becomes large and the long-term sealing property is lost. On the other hand, if it is larger than the stated value, the elastic modulus will be as hard as 1 to 3 x 10 dyne/CTl2, deformation will be large at high temperatures and low temperatures, and the sealing performance will be lost. Note that the rubber compound filler is an element that affects thermal deformation. This filler includes clays, mica, talc, 6 arrows, silicon oxide, 7J lucium carbonate, surface treatment,
Calcium carbonate, magnesium carbonate, carbon black, and filled resins include phenol, melamine, urea, ethylene vinyl acetate, unsaturated esters, and acrylic resins. No, rubber processing aids, plasticizers, pigments, etc. are blended with rubber to form the constituent material of the stopper body (1), but the amount of rubber compounded should be 20 to 60% by weight, preferably 30 to 50% by weight. is suitable for sealing electrolytic capacitors. The material of the fluororesin layer (2) laminated on the surface portion or the entire surface of the stopper body (1) includes a copolymer of tetrafluoroethylene and ethylene (abbreviated as E T' F E),
Copolymer of tetrafluoroethylene and hexafluoropropylene (abbreviated as FEP), copolymer of tetrafluoroortin and perfluoroalkoxyethylene, copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (abbreviated as PFA), tetrafluoroethylene Ethylene resin (abbreviated as PTFE), chlorotrifluoroethylene resin (abbreviated as ICTFE), vinylidene butylene resin (abbreviated as ICTFE)
There are homopolymers such as PVDF (abbreviated as PVDF). The price of these resins is about 7 to 70% lower than that of IIR, EPDM.
It is 10 times more expensive and the glass transition temperature of FEP is about 210°C.
That's high. (The glass transition point of EPM, EPDM, and 11R is about -50 to -65°C.) However, if the encapsulation of an electrolytic capacitor is formed and used only with fluororesin, the sealing performance against temperature changes will deteriorate. Also fluororesin and EPM. Even if EP[)M and (IR) are mixed, they cannot be mixed uniformly, and furthermore, they cannot be co-crosslinked. Therefore, a hard product with good sealing performance cannot be obtained.
If the rubber surfaces of EPDM and IIR are simply laminated with resin, the adhesion between the rubber and resin layers will be poor and bubbles will form. For this purpose, if the resin surface is specially treated and bonded at the same time as crosslinking of the plug body (1), φ [separation force 0.5 kg/
CW1 or higher. This surface treatment technology includes
There are plasma treatments such as glow discharge and arc discharge.This treatment involves attaching electrons, atoms, ions, radicals, etc. to the resin surface.In this case, vacuum, nitrogen, ammonia A
7. If it is carried out in oxygen or helium, the resin will have a sputtering effect and the peeling force will increase. Other resin surface treatment methods include a brimer method in which a mixed agent of a silane coupling agent, sodium, naphthalene, and human 07 run is applied. Fluororesin is a rubber plug (A) that has rubber elasticity and chemical and solvent resistance by laminating the entire surface of the plug body with a resin that can withstand high temperatures and long periods of time with all electrolytes. In order to reduce the product price, it is possible to laminate fluororesin only on the surface exposed on the inside of the capacitor to make the outside air contact surface a rubber surface, or to A resin layer of 1g1)1 norphon, polyarylate, polyethylene, hibinylidene salt, etc. is sometimes laminated on the contact surface. Since adhesion of such resins is easier than that of JN Tsutsuki I, a rubber stopper can be made by laminating films of polybutylene terephthalate, polyamide, and vinylidene chloride without treatment. Since these resins can also withstand solvents such as trichloroethane and trichloroethylene, brazing wax for electrolytic capacitors may be used as a removing agent. Next, the molding procedure for the rubber stopper (A>) will be briefly described. ■. The surface of the fluororesin film is plasma treated or primed. ■. When laminating the outside air contact surface of the stopper 1), the resin Perform plasma treatment or primer treatment appropriate for the type of material. ■, EPM or EPDM Matabanyo IIR rubber ad combination stone should be 20 to 60% by weight 11! ! In addition to blending with the compounding agent, that is, the filler and the softening agent 1.7 JII processing aid, the crosslinking density is 0.5 to 100 mol/ccx.
The crosslinking agent and crosslinking accelerator are appropriately selected from a wide variety of types so that the crosslinking ratio is 10-1. Rubber compounding is carried out using two rolls or an internal mixer to uniformly disperse the self-mixing mixture and to divide it into uniform thicknesses. ■Place the fluororesin ■ on top of the crosslinking mold, and place ■ on top of it.
A compound rubber of 0.5 is placed, and in some cases, a resin of
A rubber stopper (A>) consisting of a stopper body (1) with a crosslinking density of ~10Qmol/ccx 10' is molded. ・■, If necessary, wash with a solvent or water. Next, an example will be shown. Fluororesin surface-treated ETFE film (0.0mm thick from Mitsui Fluorochemical Industries)
Primer treatment was performed on one side of 13nu++ ChemOtsuk 607 (Lord Far East Φ Inc.). ■, Blend Example 1 of the stopper body 11R (JSRButy1218-Japanese Synthetic Rubber)
100 parts zinc oxide (#1 = Sangatsu Metal Industry)
5-part stearic acid (=
Kao soap) 1st part Q
O (Actor-Q = Kawayo Chemical Industry)
5 parts MBTS (Accel DM = Yoro Kagaku Kogyo Co., Ltd.) 8 parts Lead oxide (= Nihon Kagaku Kogyo) 10 parts Ri, t - ([)i xie = Vanderbilt
) 80 parts/paraffin - Nippon Oil
10 parts Carbon black (Geest = Tokai Carbon) 50 parts Example 2 EPDM (Mie El) T4045 = Mitsui Petrochemical Industries>
ioo part zinc oxide (#-Mitsui Kinzoku Kogyo)
5 parts stearic acid (
= Kao Soap) 1 part B13 PODIPB (Bar Power Docs 14 = Kayaku Nouri) 1.8 part Go AC (TAIC-Nippon Kasei)
1.8 parts carbon black (Sheath 1-3-Tokai Carbon)
50 parts talc (fvlistron vapor=
Sierra) 100 copies Example 3 EPDM (JSREP65=Japan Synthetic Rubber)
100 parts zinc oxide (#1 = Mitsui Kinzoku Kogyo)
5 parts stearic acid (
= Kao soap) 1
Department D1'DM (Parnock R = Ouchi Shinko Chemical)
Part 2 1) PTT (Tsukusera 1-
RA = Iriuchi 1/i Kokagaku) Part 1 MBTS (Accel OM-Kawaguchi Chemical Industry)
25 parts surface treated calcium carbonate (white ene soda=Shiraishi Kogyo) 50 parts mica (=Shiraishi Kogyo) 1 50 parts magnesium carbonate (-Tokuyama Soda)
30 parts l-reethanolamine (-Mitsui Toatsu Chemical Co., Ltd.) 2 parts Example 4 Comparative example 1 The above formulation was prepared using two rolls (8X, 16
■, Vulcanization test vulcanization mold (J I 805113-CQ922M2A6
A surface-treated Teflon FEP (83 W = 18 mm H: 14 Il 1 m T nia mm) was placed, a compounded rubber was placed thereon, and molding and crosslinking was performed under the vulcanization conditions listed in the table. Example 1 Example 2 Example 3 Example 3 Example 4
Comparative Example 1 Comparative Example 22 Rubber content (%) 37.7 3[1,540,940,
943,47373 (kg/cm) 1.1
1.3 1.8 1.1 2,61.7
1,4■ Crosslinking density (mol/'cc 1.5 9 +
0 2.3 2.8 40 52
xlO') ■ Density 1.1 degree (moisture 111 fl) 48011i 0.03 0.21
0.48 0.52 0.32 2.32
1.72■ Compression set (%) 100℃ 9 11 15
21 23 37 32×70 hours [phase]) Peeling force A peeling test between the fluororesin layer (2) and the stopper body (1) is conducted in accordance with JISK [Vulcanized Rubber Physical Test Method]. Crosslinking density - Test method "Rubber test method" (Japan Rubber Association 1981 Mitsuyuki P.
210>, F 1ory -Re
Calculate the hner formula with reference 1. Sealing degree - Accurately weigh 2g of calcium chloride, put it in a bottle, and measure the thickness.
Cover the cylindrical rubber stopper (A) with a diameter of 5 mm and 201111111, and place it in a constant temperature and humidity chamber with a humidity of 100% and a temperature of 80°C.
Leave to stand and measure water absorption of calcium chloride using Karl Fischer reagent. Compression set = J [Performed in accordance with 5K6031 [Vulcanized rubber physical test method]. 4. Test results The rubber compounding amount and crosslinking density are shown in the table, and the crosslinking temperature and crosslinking time were adjusted to be suitable for sealing an electrolytic capacitor. Among them, in Example 3-2, since the crosslinking temperature was lowered, the crosslinking density was also lowered, resulting in poor sealing performance. Note that the compression set also increases. A comparison was made with respect to natural rubber in Comparative Examples 1 and 2, but
Peeling is large, but compression set is also large and sealing performance is poor. Although not listed in the table, the ETFE film surface is not treated,
If the compounded rubber is placed as is and cross-linked, the peel force will be 0.
．． 1 to 0.2 ka/cm, which is inferior. In the above example, tests were conducted on a laminated product with only one side of the stopper body (1), but products with a resin layer (3) such as polyethylene on the entire surface or the surface in contact with the outside air can also be manufactured using the same process. obtain. 4. Brief Description of the Drawings FIGS. 1 to 3 are sectional views showing electrolytic capacitors sealed with rubber plugs according to embodiments of the present invention. In the figure, A shows a rubber stopper 1, a stopper body 2, a fluororesin layer 3, and another synthetic resin layer.

Claims (1)

[Claims] ■ The blending ratio of ethylene propylene rubber, ethylene propylene terpolymer or butyl rubber is 20% of the other blending ingredients.
~60% by weight and the crosslinking density is 0.5~100mo
1/ccx 10-4, and a fluororesin layer that is integrally laminated on at least the surface portion of the plug body that comes into contact with the electrolyte in parallel with the cross-linking molding of the plug body. Rubber plug for electrolytic capacitors. (2) The rubber plug for an electrolytic capacitor according to claim 1, wherein the fluororesin layer is laminated over the entire surface of the plug body. (2) The rubber plug for an electrolytic capacitor according to claim 1, wherein the fluororesin layer is laminated on a surface portion of the plug body that comes into contact with the electrolyte, and the remaining surface portion is laminated with another synthetic resin layer. ■ The fluororesin layer is plasma-treated at the joint surface with the plug body (claim 1 or 2).
Rubber plug for an electrolytic capacitor according to item 1 or 3. ■ Claim 1 or 2, wherein the fluororesin layer is treated with a primer on the joint surface with the plug body.
Rubber plug for an electrolytic capacitor according to item 1 or 3.