JP4641808B2 - Method for producing a membrane for ion exchange membrane - Google Patents

Description

  The present invention relates to a method for producing an ion exchange membrane precursor membrane that is introduced into an ion exchange membrane by introducing ion exchange groups, and more specifically, a polymerizable paste is applied to a base sheet. The present invention relates to a method for producing an ion exchange membrane raw film by carrying out polymerization in a state where a polymerizable film produced by impregnation is wound around a take-up roller.

Conventionally, a so-called paste method is known as a method for producing an ion exchange membrane. In this method, a base sheet having a function as a reinforcing material is coated or impregnated with a polymerizable paste to produce a polymerizable sheet having a base sheet inside a layer made of the polymerizable paste. By polymerizing the polymerizable paste to produce a raw film (ion exchange membrane raw film) to be used for introduction of ion exchange groups, by introducing various ion exchange groups into this raw film, It manufactures (refer patent document 1, 2).
Shoko 39-27861 Japanese Patent No. 3193522

  By the way, in the actual production process, in many cases, the original film used for introducing the ion exchange group is formed by applying or impregnating a base material sheet with a polymerizable paste to form a polymerizable sheet. While a release film such as a polyethylene terephthalate (PET) film is attached to one surface of the film, the polymerizable sheet is wound up in the form of a laminate with the release film, and is thus wound around a take-up roller. It is manufactured by polymerizing a polymerizable paste in the state. This is because this method is suitable for continuous production and can efficiently produce a raw film.

  However, in the case of producing a raw film by polymerizing a polymerizable paste while the polymerizable sheet is wound on a winding roller, in order to further increase the production efficiency, the number of windings of the polymerizable sheet by the winding roller is increased. However, if the number of turns is increased, the heat generated by the polymerization is not efficiently dissipated outside the roller, and heat is accumulated excessively, resulting in deterioration of the base sheet or abnormal polymerization reaction. Or progress. Therefore, when an ion exchange group is introduced into the raw membrane thus obtained to form an ion exchange membrane, the burst strength is lowered and the electrical resistance of the membrane is increased. Sometimes. Therefore, the actual situation is that the number of windings of the polymerizable sheet is limited.

  Therefore, the object of the present invention is to increase the number of windings of the polymerizable sheet by the winding roller and to polymerize the polymerizable paste in the rolled-up polymerizable sheet, thereby achieving high productivity for an ion exchange membrane. It is an object of the present invention to provide a method for producing an original film without causing deterioration in quality.

According to the present invention, a polymerizable sheet in which a base sheet is embedded in a layer made of a polymerizable paste containing a polymerizable monomer is wound while a release film is attached to one surface thereof. A method for producing an ion-exchange membrane raw film by polymerizing the polymerizable paste in a state where a polymerizable sheet with a release film attached continuously by a roller is wound around a take-up roller In
An ion exchange characterized in that a polymerization initiator and a chain transfer agent are blended in the polymerizable paste, and the polymerizable paste is polymerized so that the total thickness of the polymerizable sheet on the winding roller is 10 mm or more. A method for producing a membrane membrane is provided.

In the production method of the present invention, in general,
(1) blending the chain transfer agent in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the polymerizable monomer;
(2) The outer diameter of the winding roller is 0.1 m or more,
(3) The thickness of the base sheet is in the range of 10 to 500 μm, and the thickness of the polymerizable sheet is in the range of 10 to 1000 μm.
Is preferred.

  In the present invention, polymerization is performed in a state where the polymerizable sheet is wound on a winding roller until the total thickness of the polymerizable sheet becomes 10 mm or more, and the production efficiency is increased by increasing the number of windings of the polymerizable sheet. However, a particularly important point is that a chain transfer agent is blended in the polymerizable paste.

  That is, when a release film is attached to the polymerizable sheet and wound with a winding roller, the winding is performed so that the total thickness of the polymerizable sheet (that is, excluding the thickness of the release film) is 10 mm or more. When the polymerizable paste in such a polymerizable sheet is polymerized, there is a large gap between a portion located inside the polymerizable sheet (winding roller surface side) and a portion located on the outer surface side. It is considered that a temperature difference occurs, and as a result, the quality of the obtained original film is degraded. That is, in the portion located on the outer surface side, the polymerization heat is easily dissipated into the atmosphere, but in the portion located in the inside, the releasable film is interposed therebetween, so that the polymerization heat is external. As a result, the portion located inside the polymerizable sheet becomes considerably hotter than the portion located on the outer surface side. For this reason, wrinkles are generated in the obtained original film, particularly in the interior located on the surface side of the take-up roller, or the strength is reduced due to deterioration of the base material sheet, resulting in variations in physical properties. .

  However, in the present invention, a chain transfer agent is blended in the polymerizable paste together with the polymerizable monomer. When the chain transfer agent is present in the polymerization system, the growing polymer radical generated by the reaction between the monomers reacts with the chain transfer agent, and the radical is generated from the polymer and the transfer agent radical by chain transfer. . Therefore, as much as the growth stop due to chain transfer is added, the rapid polymerization growth is alleviated and the polymerization heat is suppressed. That is, as a result of the suppression of the polymerization heat, the temperature rise in the portion located inside the polymerizable sheet is effectively mitigated, and the total number of turns of the polymerizable sheet becomes 10 mm or more. Thus, it was possible to produce a raw film without causing quality degradation.

  In the present invention, if the chain transfer agent is blended in a larger amount than necessary, the molecular weight of the resin constituting the original membrane is reduced, and a predetermined exchange capacity cannot be obtained even if a reduction in membrane strength and exchange groups are introduced. In general, the blending amount is preferably 0.5 to 5 parts by weight per 100 parts by weight of the polymerizable monomer. In addition, as the total thickness of the polymerizable sheet on the take-up roller exceeds 10 mm, the temperature of the polymerizable sheet becomes higher at the roller surface side portion, and the quality tends to deteriorate. It is preferable to increase the amount of the chain transfer agent, and therefore the chain transfer agent satisfies the above formula (1) on the condition that the amount of the chain transfer agent is within the above range. Is most preferable.

  In the present invention, by adding the chain transfer agent in this manner, for example, the total thickness of the polymerizable sheet wound on the take-up roller can be increased to 10 mm or more.

The present invention will be described below based on specific examples shown in the accompanying drawings.
FIG. 1 is a diagram showing a production and winding process of a polymerizable sheet carried out in the present invention,
FIG. 2 is a view showing the layer structure of the polymerizable sheet obtained in the step of FIG. 1 together with the release film.

  With reference to FIG. 1, in the production and winding process of the polymerizable film, the substrate roller 3 around which the substrate sheet 1 is wound, the coating tank 7 filled with the polymerizable paste 5, the winding roller 9, and A release material roller 13 around which the release film 11 is wound is disposed.

  The substrate sheet 1 is wound up from the substrate roller 3 by a winding roller 9 via a plurality of tension rollers 15, and is immersed in the polymerizable paste 5 in the coating tank 7 in the middle thereof. Thus, by forming a layer of the polymerizable paste 5 having the base sheet 1 inside, a polymerizable sheet indicated by 20 as a whole is produced.

  The releasable film 11 is wound on the core film 1 by the take-up roller 9 from the release material roller 13 through the plurality of tension rollers 21. The release film 11 is attached to one surface of the polymerizable film 20 by the attaching roller 23 arranged at a position facing the substrate 9 and elastically biased, and laminated with the release film 11. In this form, the polymerizable sheet 20 is wound around the winding roller 9.

  As shown in FIG. 2, the polymerizable sheet 20 thus produced is composed of a layer of the polymerizable paste 5 having the base sheet 1 inside, and on one surface thereof, the release sheet is formed. The adhesive film 11 is affixed.

  In the present invention, it is important to wind up the polymerizable sheet 20 by the winding roller 9 so that the total thickness (thickness excluding the release film 11) is 10 mm or more, particularly 20 mm or more. . That is, in the present invention, by increasing the number of windings of the polymerizable sheet 20 on the take-up roller 9, the long polymerizable sheet 20 is produced at a time, and the production efficiency is increased. Incidentally, when the number of windings of the polymerizable sheet 20 increases and the total thickness of the polymerizable sheet 20 on the take-up roller 9 exceeds 10 mm, temperature unevenness easily occurs during polymerization, which will be described later. Although deterioration of the quality of the original film occurs, such quality deterioration can be avoided by blending a chain transfer agent in the polymerizable paste, as will be described later.

<Base material sheet 1>
In the present invention, as the base sheet 1, those conventionally used as a base material for reinforcing ion exchange membranes are used without any limitation. For example, polyvinyl chloride, polyethylene, polypropylene, polybutene or these as materials Polyolefins such as copolymers or blends are used.

  Although the base material sheet 1 has the form of a woven fabric normally, it may have forms, such as a nonwoven fabric, a net | network, and a porous sheet. The single yarn of the woven fabric may be either a monofilament or a multifilament. Furthermore, although the electrical resistance of the ion exchange membrane which can be obtained when the basis weight of the warp yarn or weft yarn in the base material sheet 1 is smaller can be reduced, in general, in order to suppress a decrease in form retention due to yarn misalignment, generally 1 square inch. It is preferable that the number of hits is set in a range of about 10 to 500. In addition, if a device such as partial fusion of the intersections of single yarns is used, a woven fabric having a mesh number of 10 or less can be used as a base sheet, for example, a composite in which the core portion is polypropylene and the sheath portion is polyethylene. If filaments are used and the polyethylene part at the intersection is fused, a woven fabric having a small number of meshes can be used as the base sheet 1. Although the thickness of such a base material sheet 1 is not specifically limited, Usually, it exists in the range of 10-500 micrometers.

  The base sheet 1 made of polyolefin is calendered to improve the surface smoothness of the base sheet 1 by compressing the intersection of the warp and weft yarns, or by heat-treating the base sheet 1 in advance. The dimensional change of the base sheet 1 in the polymerization step described later can also be suppressed. Furthermore, well-known surface treatments, such as a corona discharge process and a chlorosulfonic acid process, can be performed and the adhesiveness of the base sheet 1 and the ion exchange resin part derived from the polymeric paste mentioned above can also be improved.

<Polymerizable paste 5>
The polymerizable paste 5 applied to the base sheet 1 forms a resin that introduces ion exchange groups, includes at least a polymerizable monomer and a polymerization initiator, and also includes a viscosity modifier. Furthermore, although it contains a crosslinking agent if necessary, in the present invention, a chain transfer agent is blended in such a polymerizable paste, and the chain transfer agent reduces the heat of polymerization and generates heat during polymerization. To avoid degradation of the quality of the original film due to

  As the polymerizable monomer, a known monomer used for the formation of an ion exchange resin is used without any limitation. For example, a monomer having a functional group suitable for introduction of an ion exchange group or an ion exchange A monomer having a group as a functional group is used. Examples of the monomer having such a functional group include styrene, vinyl toluene, vinyl xylene, α-methyl styrene, acenaphthylene, vinyl naphthalene, α-halogenated styrene, α, β, β′-trihalogenated styrene, chloro. Styrene and the like are typical, but particularly when the original membrane is used for forming a cation exchange membrane, α-halogenated vinyl sulfonic acid, α, β, β′-halogenated vinyl sulfonic acid, methacrylic acid, Acrylic acid, styrene sulfonic acid, vinyl sulfonic acid, maleic acid, itaconic acid, styrene phosphonylic acid, maleic anhydride, vinyl phosphoric acid, and salts and esters thereof are suitable. When used for formation, vinyl pyridine, methyl vinyl pyridine, ethyl vinyl pyridine, vinyl pyrrolidone, vinyl Carbazole, vinyl imidazole, aminostyrene, alkylaminostyrene, dialkylaminostyrene, trialkylaminostyrene, methyl vinyl ketone, chloromethyl styrene, acrylic amide, acrylamide, oxynium, styrene, vinyl toluene, etc. are suitable. A monomer may be used individually by 1 type, or can also be used in combination of 2 or more type mutually copolymerizable.

  Moreover, as said monomer, what can be copolymerized with the crosslinking agent mentioned later is contained, or you may contain as a comonomer. Monomers copolymerizable with such crosslinking agents include styrene, acrylonitrile, ethyl styrene, vinyl chloride, acrolein, methyl vinyl ketone, maleic anhydride, maleic acid, maleic acid salts or esters, itaconic acid, Examples thereof include salts or esters of itaconic acid.

  The polymerization initiator used together with the above-described monomer is appropriately selected according to the type of the base sheet 1.

  For example, when the base sheet 1 made of polyvinyl chloride is used, a radical polymerization initiator having a 10-hour half-life temperature of 110 ° C. or less, specifically, benzoyl peroxide, methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide Oxide, cyclohexane peroxide, methylcyclohexane peroxide, isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, p -Chlorobenzoyl peroxide, 1,1-di-tert-butylperoxy-trimethylcyclohexane, 1,1-di-tert-butylperoxy-cyclohexane, 2,2-di- (tert-butylperoxy) -butane 4,4-di-tert-butyl Peroxyvaleric acid-n-butyl ester, 2,4,4-trimethylpentylperoxy-phenoxyacetate, α-cumylperoxyneodecanoate, tert-butylperoxyneodecanoate, tert-butylperoxybiba Tert-butylperoxy-2-ethylhexanoate, tert-butylperoxy-isobutyrate, di-tert-butylperoxy-hexahydroterephthalate, di-tert-butylperoxyazelate, tert-butylperoxy -3,5,5-trimethylhexanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate and the like are used.

  When the polyolefin base sheet 1 is used, a radical polymerization initiator having a 10-hour half-life temperature of 110 ° C. to 170 ° C., specifically, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide Α, α′-bis (tert-butylperoxy-m-isopropyl) benzene, di-tert-butyl peroxide, tert-butyl hydroperoxide, di-tert-amyl peroxide, tert-butyl cumyl peroxide, Dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, cumene hydroper Oxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexa And 2,5-dimethyl-2,5-dihydro peroxy f relaxin-3 used.

  The polymerization initiator is usually used in an amount of 0.5 to 10 parts by weight per 100 parts by weight of the polymerizable monomer. The polymerization initiator is preferably used in a relatively small amount. That is, by setting the blending amount of the polymerization initiator to be small, it is advantageous for suppressing the temperature rise of the polymerizable sheet 20 at the time of polymerization and suppressing the deterioration of the quality of the original film obtained from the polymerizable sheet 20. It becomes.

  The cross-linking agent used in combination with the above-described polymerizable monomer and polymerization initiator as necessary is used to increase the strength of the film and the like. As such a cross-linking agent, m-, p -Or divinyl compounds such as o-divinylbenzene, divinylsulfone, butadiene, chloroprene, isoprene, trivinylbenzene, divinylnaphthalene, diallylamine, triallylamine, and divinylpyridine can be exemplified. Such a crosslinking agent is generally used in an amount of 5 to 20 parts by weight per 100 parts by weight of the monomer.

  The polymerizable paste 5 preferably contains a matrix resin as a viscosity modifier. By adding such a matrix resin, the workability of the polymerizable paste 5 is improved, and this is used as a base material. It is possible to prevent dripping or the like when the sheet 1 is applied or impregnated, and to effectively wind the polymerizable sheet 20 by the winding roller 9.

  Examples of such a matrix resin include ethylene-propylene copolymer, saturated aliphatic hydrocarbon polymer such as polybutylene, styrene polymer such as styrene-butadiene copolymer, polyvinyl chloride, or vinyl. Styrene monomers such as toluene, vinyl xylene, chlorostyrene, chloromethyl styrene, α-methyl styrene, α-halogenated styrene, α, β, β'-trihalogenated styrene, monoolefins such as ethylene and butylene, Those obtained by copolymerizing conjugated diolefins such as butadiene and isoprene can be used. The molecular weight of such a matrix resin is usually in the range of 1,000 to 1,000,000, particularly 50,000 to 500,000, and the polymerizable paste 5 can be used in an amount sufficient to ensure an appropriate viscosity depending on the molecular weight. Formulated in.

  Further, in the polymerizable paste 5, a plasticizer such as dioctyl phthalate, dibutyl phthalate, tributyl phosphate, styrene oxide, or an alcohol ester of a fatty acid or an aromatic acid, or an organic solvent may be blended if necessary. Good.

  In this invention, a chain transfer agent is mix | blended in the polymeric paste 5 mentioned above. That is, in the present invention, in order to increase the production efficiency, the number of windings of the polymerizable sheet 20 by the winding roller 9 is increased so that the total thickness becomes 10 mm or more. The polymerization heat generated in the inner part of the polymer sheet 20 is confined to the inner part facing the take-up roller 9, and as a result, the inner part of the polymerizable sheet 20 becomes remarkably higher than the outer surface side, and is formed by polymerization. In the film, wrinkles are generated particularly in the inner part or the base sheet 1 is deteriorated, and polymerization unevenness occurs between the inner side and the outer side, resulting in variations in various physical properties. In the present invention, by adding a chain transfer agent to the polymerizable paste 5, chain growth is moderately suppressed, polymerization is prevented from proceeding at once, polymerization heat is reduced, and the quality of the original film as described above is reduced. The decrease can be avoided.

As the chain transfer agent, those known per se can be used. For example, mercaptans such as n-butyl mercaptan, t-butyl mercaptan, lauryl mercaptan and organic sulfur compounds, carbon tetrachloride, isopropylbenzene, 2, 4 -Diphenyl-4-methyl-1-pentene, terpinolene, myrcene, limonene, α-pinene, β-pinene and other terpenoids, trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercapto Β-mercaptopropionic acids such as propionate), organophosphorus compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, thioglycolic acid, 4-t-butylcatechol Etc. can be illustrated.

  Such a chain transfer agent is usually added in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the polymerizable monomer. That is, if the blending amount is small, the effect of suppressing the polymerization heat due to chain transfer is reduced, and the temperature rise in the polymerizable sheet 20 (particularly the inside located on the surface side portion of the take-up roller 9) during polymerization is effectively suppressed. Cannot be achieved, and the effect of suppressing the deterioration of the quality of the original film tends to be reduced. Moreover, when it mix | blends abundantly than the said range, there exists a possibility of causing the fall of the film | membrane intensity | strength etc. by the molecular weight fall of the resin which comprises a raw material film | membrane which falls and comprises a raw film.

Moreover, as the total thickness of the polymerizable sheet 20 on the take-up roller is increased beyond 10 mm, the temperature of the polymerizable sheet 20 at the roller surface portion becomes a high temperature, it is likely to occur the degradation, this thickness Accordingly, it is preferable to increase the blending amount of the chain transfer agent. Thus, by mix | blending a chain transfer agent , polymerization heat can be relieve | moderated and quality deterioration can be prevented much more effectively.

<Polymerizable sheet 20>
In the present invention, the base sheet 1 is polymerizable by immersing the base sheet 1 in the coating tank 7 in the polymerizable paste 5 in which the polymerization initiator amount is set in a predetermined range as described above. A polymerizable sheet 20 embedded in the layer of paste 5 is produced. Accordingly, the thickness of the polymerizable sheet 20 is thicker than that of the base sheet 1 and is usually in the range of about 10 to 500 μm.

<Releasable film 11>
In the present invention, the release sheet 11 is attached to one surface of the polymerizable sheet 20 formed by immersing the base sheet 1 in the polymerizable paste 5 in the coating tank 7, The film is wound around the winding roller 9 in the form of a laminate of the conductive film and the polymerizable sheet 20. That is, if the release film 11 is not attached, the polymerizable sheet 20 is integrated on the take-up roller 9 and the sheet shape is damaged.

  Such a releasable film 11 can be used without any limitation as long as it has heat resistance that can be endured in a polymerization step described later, and can be easily peeled off after polymerization, such as low-density polyethylene, High-density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, or random or block copolymers of α-olefins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, etc. Polyolefin, ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, ethylene / vinyl compound copolymer such as ethylene / vinyl chloride copolymer, polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene・ Styrene resins such as styrene copolymers, polyvinyl chloride, polyvinyl chloride Ridene, vinyl chloride / vinylidene chloride copolymer, polyvinyl compounds such as polymethyl acrylate and polymethyl methacrylate, polyamides such as nylon 6, nylon 6-6, nylon 6-10, nylon 11 and nylon 12, polyethylene terephthalate, A material composed of a thermoplastic polyester such as polybutylene terephthalate or polyethylene naphthalate, polycarbonate, polyphenylene oxide, or the like, a biodegradable resin such as polylactic acid, or a mixture thereof, in the polymerizable paste 5 Polyester films such as polyethylene terephthalate (PET) are preferred, particularly in terms of good heat resistance and releasability, although such films can be used depending on the type of monomer and the like. It may be biaxially stretched. The thickness of the releasable film 11 is usually preferably in the range of about 50 to 200 μm. If it is too thick, the flexibility of the film will be reduced, and it will be difficult to wind the film by the winding roller 9.

<Winding roller 9>
The size of the take-up roller 9 used for winding the laminate of the polymerizable sheet 20 and the release film 11 is not particularly limited, but if it is too small, Since the number of windings must be remarkably increased and the total thickness of the polymerizable sheet 20 becomes remarkably thick, it is generally preferable that the outer diameter is 0.1 m or more. Furthermore, the winding roller 9 preferably has an appropriate heat capacity. For example, the heat capacity per 1 kg of the monomer present in the wound polymerizable sheet 20 is about 2 to 15 kJ / ° C. Thus, it is preferable that the thickness t of the winding roller 9 is set. That is, when the heat capacity of the take-up roller 9 is within this range, the heat of polymerization generated in the polymerizable sheet 20 is absorbed by appropriate heat transfer, and the abnormal temperature rise of the polymerizable sheet 20 due to the heat of polymerization is suppressed. be able to.

<Polymerization>
In the present invention, the polymerization is performed in a state where the polymerizable sheet 20 is wound until the total thickness becomes 10 mm or more as described above. That is, the winding roller 9 is introduced into the polymerization apparatus in a state where the polymerizable sheet 20 with the release film 11 attached is wound, and the atmosphere in the polymerization apparatus is heated to a predetermined polymerization temperature. Thus, polymerization of the polymerizable paste 5 is performed, and a raw film for introducing ion exchange groups can be obtained.

  Although the polymerization temperature varies depending on the type of polymerization initiator used, it is generally preferable to set the polymerization temperature in consideration of the melting point of the base sheet 1. For example, when the substrate sheet 1 is polyvinyl chloride or polyolefin, it is preferable to perform polymerization at 140 ° C. or lower. In the present invention, as described above, since the polymerization initiator amount is adjusted to a predetermined range, the polymerization does not proceed at once, but the polymerization proceeds gradually, so that the polymerization heat is uniformly distributed in the polymerizable sheet 20. For example, the temperature inside the take-up roller 9 does not become high, and the deterioration of the quality of the obtained original film can be effectively avoided.

<Raw membrane>
The original membrane obtained as described above is used as a cation exchange membrane or an anion exchange membrane after ion exchange groups are introduced after the heat of polymerization peels off the release film 11.

  The ion exchange group is introduced by means known per se, for example, sulfonation, chlorosulfonation, chloromethylation, amination, quaternary ammonium chlorination, phosphoniumation, sulfoniumation, hydrolysis and the like. Is done. The amount of ion exchange groups introduced is not particularly limited, but the ion exchange capacity is usually in the range of 0.1 to 20 meq / g · dry membrane, particularly 0.5 to 3 meq / g · dry membrane. Is good.

  The superior effect of the present invention is illustrated in the following example.

(Examples 1-3)
80 parts by weight of chloromethylstyrene, 10 parts by weight of styrene, 5 parts by weight of industrial divinylbenzene, 5 parts by weight of styrene-butadiene rubber, 5 parts by weight of dioctyl phthalate, 6 parts by weight of radical polymerization initiator benzoyl peroxide and chain transfer agent 2, 4-Diphenyl-4-methyl-1-pentene was added in the amount shown in Table 1 to obtain a paste mixture.
Next, the paste mixture was applied to a vinyl chloride base sheet (thickness: 100 μm), and the polyester film was wound on a winding roller as a release film so that the total thickness of the polymerizable sheet was 30 mm. Thereafter, the take-up roller was put in an autoclave and kept at 75 ° C. for 8 hours in nitrogen gas at a pressure of 0.4 Mpa. The obtained original film was immersed in trimethylamine at room temperature for 24 hours to perform a quaternization reaction. The membrane performance of the obtained ion exchange membrane is shown in Table 1.

(Examples 4 to 5)
10 parts by weight of chloromethylstyrene, 80 parts by weight of styrene, 5 parts by weight of industrial divinylbenzene, 15 parts by weight of tributyl citrate, 40 parts by weight of vinyl chloride powder, 3 parts by weight of radical polymerization initiator benzoyl peroxide and chain transfer agent 2 , 4-Diphenyl-4-methyl-1-pentene was added in the amount shown in Table 2 to obtain a paste mixture.
Next, the paste mixture was applied to a vinyl chloride substrate sheet (thickness: 100 μm), and the polyester film was wound on a winding roller as a release film so that the total thickness of the polymerizable sheet was 20 mm. Thereafter, the take-up roller was placed in an autoclave and kept at 80 ° C. for 5 hours in nitrogen gas at a pressure of 0.4 Mpa. The obtained original membrane was immersed in a 1: 1 mixed solution of 98% concentrated sulfuric acid and 90% chlorosulfonic acid at 40 ° C. for 60 minutes. The membrane performance of the obtained ion exchange membrane is shown in Table 2.

(Comparative Examples 1-2)
The same procedure as in Example 1 was conducted except that 2,4-diphenyl-4-methyl-1-pentene was added in the amount shown in Table 3. Table 3 shows the membrane performance of the obtained ion exchange membrane.

The figure which shows the preparation and winding-up process of the polymeric sheet implemented by this invention. The figure which shows the layer structure of the polymeric sheet obtained at the process of FIG. 1 with a release film.

Explanation of symbols

1: base sheet 5: polymerizable paste 9: take-up roller 11: release film 20: polymerizable sheet

Claims (4)

A polymerizable sheet in which a base sheet is embedded inside a layer made of a polymerizable paste containing a polymerizable monomer is continuously wound by a take-up roller while a release film is attached to one surface thereof. In a method for producing an ion-exchange membrane raw film by polymerizing the polymerizable paste in a state where a polymerizable sheet with a release film attached is wound around a winding roller,
An ion exchange characterized in that a polymerization initiator and a chain transfer agent are blended in the polymerizable paste, and the polymerizable paste is polymerized so that the total thickness of the polymerizable sheet on the winding roller is 10 mm or more. A method for producing a membrane film.   The method according to claim 1, wherein the chain transfer agent is blended in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the polymerizable monomer. The manufacturing method according to claim 1 , wherein an outer diameter of the winding roller is 0.1 m or more. The manufacturing method according to any one of claims 1 to 3 , wherein a thickness of the base sheet is in a range of 10 to 500 µm, and a thickness of the polymerizable sheet is in a range of 10 to 1000 µm.

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