Electrolysis diaphragm and method for its manufacture

[Detailed Description of the Invention]

The present invention relates to the barrier membrane for electrolysis which used as the substrate the fluorine-ized resin in which remarkable hydrophilicity is shown, and the manufacturing process of this barrier membrane. The conventional barrier membrane made from asbestos for electrolysis arranged from several years before on the negative pole of the electrolysis vessel for acquiring especially chlorine and Sex soda is gradually replaced with by the barrier membrane which used as the substrate the fluorine-ized resin which may contain a fiber reinforced. Although such barrier membrane especially shows many advantages which Attribution to the chemical nature of fluorine-ized resin, it shows remarkable inconvenience peculiar to this resin that Attribution to that low wettability similarly. This fault is reduced when textiles like asbestos are blended so much in barrier membrane, but the danger that this material will give a user is known. Many solution is proposed in order to lose this inconvenience. For example, it adds to use of a specific additive agent like the oxide of titanium, zirconium, or aluminum, hydroxide, or asbestos, Processing introduction of a sulfur content machine, especially a sulfone group or the resin used for U.S. Pat. No. 4153520 like a statement on the spot, or adding the resin which the statement sulfonated [ French patent / No. 2152988 ] beforehand was proposed. It is I and It was that it is acquirable by the easy way hydrophilic barrier membrane, i.e., the barrier membrane by which humidity is easily carried out with an electrolysis solution, gives desirable character here to electrolysis at the time of contact of concentrated alkaline solution especially. Especially one of the objects of the present invention is in the micro-cellular barrier membrane by which at least 1 portion on Then and the surface of internal of the fine pores is covered with the micro-cellular barrier membrane which used as the substrate the fluorine-ized resin used for electrolysis of alkali metal halide by the copolymer of unsaturated carboxylic acid and a nonionic unsaturated monomer. Other objects of the present invention form the porous sheet which used fluorine-ized resin as the substrate, Impregnating processing of this sheet is carried out with the mixture (this mixture shows small viscosity) containing at least one sort of unsaturated carboxylic acid, at least one sort of nonionic monomers, and at least one sort of polymerization initiators, The mixture of The is made to copolymerize and it is in the manufacturing process of the micro-cellular barrier membrane which consists of subsequently to after being impregnated of Comonomer in this sheet, and copolymerization Drainage(ing) from that sheet. Such micro-cellular barrier membrane can be manufactured by various kinds of methods, and, now, many of these methods are common knowledge. Especially the fluorine-ized resin that can be used is poly tetrafluoroethylene, Poly truffe Ruol ethylene, poly hexafluoroethylene, poly Buddha-ized vinyl, Poly halogeno ethylene which contains polyvinylidene fluoride, poly Perfluor alkoxy ethylene, 1, two chlorine atoms and 3, or two fluorine atoms in each ethylene portion, It is a copolymer with the halogenation unsaturated hydrocarbon which is partially fluorine-ized at least with poly halogeno propylene especially corresponding to Polychlorotrifluoride ethylene and these, ethylene, and (or) propylene, and has 2 or three carbon atoms. Also in these compounds, especially the product known as a brand name "HALAR" from an allied chemical company can be raised from pro shoe Simik Yujinu Culmann as "SOREFLON" as a brand name "TEFLON" from a jupon company. These resin can be strengthened by various kinds of textiles like organic textiles, such as halogenation especially fluorine-ized polypropylene or polyethylene, and poly halogeno Vinylidene, by asbestos, glass, quartz, zircon, a mineral fiber like carbon fiber, or a case. Then of the rate of a fiber reinforced is good by O~200% of the weight of resin. As already described above, when asbestos of the comparatively high rate which is 30% or more of the weight of resin is given, barrier membrane has the wettability which can be satisfied even if it generally does not process an addition. The total porosity rate is 50~95 (fl) preferably, and the equivalent average diameters of fine pores are 0.1~12 micrometers, preferably 0.2~6 micrometers. This equivalent diameter is a diameter of the theoretical cylindrical fine pores which make the fluid of hypoviscosity pass at the same speed as ideal fine pores under predetermined pressure. The carboxylic monomer used has 1 or two carboxyl groups. As for this, Then is good at acrylic acid or methacrylic acid, those halogenated derivatives, phenylacrylic acid, Etah Kurile acid, maleic acid, itaconic acid, butyl acrylic acid, vinyl benzoic acid, etc. Acrylic acid and methacrylic acid are preferred. Then of a nonionic monomer is good at what has one ethylenic linkage, for example, styrene, methylstyrene, ethyl vinyl benzene, Krol, full Orle- styrene or - methylstyrene and vinyl pyridine, or - pylori boss. They can promote reticulated-ization of the polymer layer which could show unsaturated [ two or more ], therefore was generated. For example, the divinylbenzene, especially the desirable Para opposite-sex object, trivinylbenzene, Divinyl naphthalene, Divinyl ethyl or - methylbenzene, 1 and 3, 4-Trivi nil cyclohexane, etc. can be raised. A nonionic monomer 1 unsaturated [ at least one sort of ] and the monomer of saturation can be used simultaneously, and this is preferred. Carrying out a deer, the numerator of two sorts of these monomers or the rate of the number of portions is 0.1~10, preferably 0.4~2.5. The divinylbenzene ethyl vinyl benzene mixture which can be obtained in a market is used advantageously. Although the weight percentages of unsaturated acid [ as opposed to / nonionic / a monomer and / the mixture of a monomer in carboxyl ] are 40~98 % of the weight, preferably 70~95 % of the weight, this monomer mixture -- a case -- and it is important that the low viscosity of 2 or less cp is preferably shown so that a diluent may preferably be added and it can permeate under decompression slight in the fine pores of a micro-cellular substrate (lower 1~100 mmHg than atmospheric pressure). It is a non-Elective diluent so that a deer may be carried out and the quantity of a monomer and the distribution of a porosity rate which are introduced may be carried out to the mixture of a monomer 11b1 m, They are methanol, ethanol, isopropanol, butanol, and acetone especially, it has methyl isobutyl ketone, dioxane, Krol or Diprom methane, and 2~10 carbon atoms -- halogenation . Being done -- aliphatic hydrocarbon with things, Dimethylform amide, Dimethyl aceto amide, dimethyl sulfoxide, etc. are added. Ethanol is a desirable diluent. Generally, a diluent has the surface tension of a comparatively small value with ambient air temperature, and must be able to mix it with water depending on Comonomer and the case. The diluent of 1600~30 copies is preferably used per 100 weight sections of Comonomer. The copolymer formed from Comonomer diluted in this way will appear as a monomolecular layer at least in at least one pair on the surface of internal of fine pores. A radical polymerization initiator is added by the mixture of Comonomer. a temperature lower than the apparent initial softening of the fluorine-ized polymer used although a polymerization to the extent that this may be felt with ambient air temperature under the absence of active radiation (ultraviolet rays) is not made to cause -- the polymerization of Comonomer is made to cause in less than 12 hours preferably at the temperature below 100 degreeC As a polymerization initiator, benzoyl peroxide, lauroyl peroxide, peroxidation t-butyl, peroxidation cumyl, peracetic acid, or perbenzoic acid t-butyl and azobis isobutyronitrile can be raised. The temperature conditions of a polymerization can be adapted to selection of a diluent so that too early at the time of a polymerization at the spot a start may be avoided. To this, an active agent, for example, Dimethyl aniline, can be used. This makes a polymerization attain in the 40 degreeC neighborhood with benzoyl peroxide. Carrying out a deer, the manufacturing process of such wettability micro-cellular barrier membrane includes manufacture of a micro-cellular sheet as the first process. The method of using the France patent No. 2229739, No. 2280435, No. 2280609, and a Construction hole agent like [ of No. 2280435 (these are quoted as reference literature here) ] a statement for carrying this out as a desirable method can be raised. A Construction hole agent is introduced into latex of fluorine-ized resin, especially poly tetrafluoroethylene latex containing a plasticizer, And they are 900~1200, preferably a 400~900-weight section Construction hole agent to 100 weight sections of resin of latex containing 40~60% of the weight of a dry matter, 0.5~2% of the weight of a plasticizer and 1~20-weight section water are added, Rolling mill forming of the sheet can be carried out from the What-strike-like thing obtained by having been agitated gently, namely, a rotor mixing this combination thing in the kneading machine which rotates below by 100rp?, this can be dried, and the temperature about the melting point of the polymer which subsequently uses this can be made to frit. Subsequently, it is removed when a Construction hole agent (this is calcium carbonate preferably) immerses in acid (this is 15~20% of the weight of acetic acid solution preferably). Especially as for a porous film, the fluorine-ized polymer to be used is mineral matter or organic textiles (asbestos). In the case of the copolymer of the ethylene which blended zircon or Fifryl-ized polyolefin, and Chlorotrifluoride ethylene, or PTFE latex It can obtain by making the electrolyte which added the surface-active agent at a rate of 5~50% of the weight of textiles including an electrolyte, i.e., 15% of that or sex soda, and 15% of sodium chloride distribute this copolymer. After carrying out dry hardening by drying of the sheet which flowed down this and was formed at the time of Overflow on the surface (Then is good at the porous negative pole as for especially this) which makes this suspension filter, it can heat to the temperature to 260degreeC, and can hold to this temperature for ~ 1 hour during 30 minutes. subsequently, the porous sheet formed in this way -- Comonomer and a polymerization initiator -- and impregnating processing is carried out with a mixture with an inactive diluent at 1 Carrying. The rate of the diluent mentioned above should be selected according to the rate of the rate of various kinds of parameters of other, a Comonomer reticulated-ized agent [ especially as opposed to unsaturated carboxylic acid ], especially divinylbenzene and a polymerization initiator, especially benzoyl peroxide. The synthetic conditions which should be careful and the combination of various kinds of parameters of other takes You intermediary selection are that 0.1~6% of the total pore volume of micro-cellular sheet 1 base material is occupied with a carboxylic copolymer before a polymerization at the spot. Then of the weight percentage of Divinyl benzene * A is good at 2.5~25 pairs per 100 copies of unsaturated carboxylic acid. Even if what is necessary is just to use a little polymerization initiators, for example, benzoyl peroxide of 5 weight sections or less per 100 weight sections of Comonomer, and a small quantity (two or less copies) uses a copolymerization catalyst like dimethylamine very much, it is not necessary to use. It can perform this being impregnated by being immersed in Yoku who put in the above-mentioned liquefied mixture, for example, and carrying out filtration under reduced pressure by 10~100muHg. A sheet may be placed on a base material, especially the negative pole depending on the case, and subsequently, in the bottom, this is introduced into a room so that temperature or active radiation, especially ultraviolet rays may make an operation of a polymerization initiator cause. It can be immersed in a fluid, for example, water. Generally temperature is below 150 degreeC too highly. And it is important that it is the temperature which does not denature structure of a micro-cellular sheet remarkably by very early separation of a diluent or destruction of an adhesion copolymer. It is 12 hours or less preferably during the polymerization (this is mostly equivalent to the half-life of the initiator to be used). A desirable polymerization method is immersed in the water of 40~100 degreeC. Various kinds of factors to the hydrostatic pressure which Attribution in the anode liquid which it takes that Table 1 shown with the following examples makes the drop in pressure or the percolation which can be satisfied if it puts in another way of the electrolysis solution which crosses barrier membrane perform, and the voltage in a tub, For example, the influence of the weight ratio between the rate of the thing used as the porosity rate of barrier membrane or its direct cause, i.e., a Construction hole agent, carboxylic acid, and a nonionic monomer and the amount of the diluent used is illustrated clearly. It turns out that the factor recollected can be chosen so that the predetermined object may be achieved. Although the example of the present invention is shown below, these are only mere illustration. Example 1 Poly tetrafluoroethylene latex of 1679 which has a part for 60% of dry extraction (brand name by pro shoe Simik Yujinu Culmann "SOREFLON"), The powdered calcium carbonate (brand name made from 0MYA "CALIBRITEl4OO") of 7009 and PEROLENE (PEROLENES.P.Z.) (solution of 629/l) of 429 are introduced. Z form rotor uniforms this mixture for 5 minutes with the WERNER type kneading machine which rotates at the rate of 45rp?. The obtained What-strike-like thing is made into a sheet shaped by a LESCUYER type cylinder mixer. Thickness shall be 1.2 mm. Original revolving speed 15rp? of a cylinder is gradually reduced to 5rpff1 in 2~4 minutes. Although the sheet formed by making it such is dried by 15 hours and then 120 degreeC by 95 degreeC for 2 hours and it is made to frit at the furnace which subsequently circulated the hot wind, the temperature is raised to 360degreeC at a rate of 100 degree/h C, and is kept for 15 minutes to the temperature. Subsequently, calcium carbonate is removed by being immersed for 72 hours into 25% of the weight of the acetic acid solution which added the surface-active agent (marketed as "ZONYLF.S.NJ from the jupon company) of 29/l. Subsequently, this barrier membrane is washed and it is immersed into ethanol for 12 hours. Subsequently, the following solution is made to Overflow under decompression of 50mmHg through the formed micro-cellular barrier membrane. The above-mentioned part is denoted by weight. Commercial divinylbenzene contains 45% of the weight of ethyl vinyl benzene, and 55% of the weight of divinylbenzene. A polymerization is made to cause by being immersed in the water of 80 degreeC for 2 hours. It is underwater saved until it is used for this barrier membrane given remarkable wettability. Subsequently, an electrolysis vessel is contacted to the reticulated iron negative pole which Gantois spread, and this is arranged. The anode consists of extract bread Strike titanium which covered the Pt-1r alloy. Inter electrode distance is 5.5 mm and it holds an electrode with the joint made of rubber. The electrolysis solution introduced into the anode room is salt water containing the sodium chloride of 3009/l. After making it operate at 200:00, an operating condition is stabilized, temperature is 85degreeC, current density is 25 A/Drrl, voltage is 3.35V, and the pressure of an electrolysis solution is 40?. That of negative pole liquid or sex soda has the concentration of 1239/l, therefore Faraday 1 yield (0H ion) is 94%. Comparative example The micro-cellular barrier membrane which manufactured carboxylic acid as mentioned above except for not applying processing by the monomer and a nonionic monomer is used on the same conditions as the electrolysis vessel of Example 1. After making it operate for 15 hours, voltage shows 4.0V and pressure rises to 60CTfL. Subsequently, these increased very quickly, the deer was carried out, and if electrolysis was not stopped, it did not become. The rate of Comonomer of the amount of calcium carbonate and the mixture for being impregnated, a diluent, and a peroxide is changed, and two examples repeat the examination of 1. although the result of the obtained versatility is shown in Table 1, it comes out in this table. The result shown in the table was measured after operating for 200 hours. If the first two control tests (1 and 2) did not suspend measurement of pressure h and voltage V 25 hours after being at the It was done time, they did not become. This is the same as examination 235. The numerical value about the used substance is a weight section, and the numerical value of calcium carbonate is against 100 copies of fluorine-ized polymers (dryness). The pressure of electrolysis solution R multiplies the hydrostatic pressure on the barrier membrane denoted by Brazing, or the height of the electrolysis solution of about 1.2 density by the number of latter. The quantity of NaOH is denoted by 9/l. yield R(0H) % is Faraday 1 yield which was generated or was calculated based on sex soda. T % is the percentage of the pore volume occupied by the dry polymer.