JP5147136B2 - Carbon dioxide adsorbent and separation or purification material - Google Patents

Description

  The present invention is a polymer formed from propiolic acid or a derivative thereof, wherein the double bond of the main chain is a cis type and forms a helical structure, and contains a crystal structure in which these helical structures are aggregated, helium, The present invention relates to a carbon dioxide adsorbing material and a separation or purification material having a property of selectively adsorbing carbon dioxide present in hydrogen, oxygen, nitrogen, carbon monoxide, hydrocarbons having 1 to 5 carbon atoms, and mixtures thereof.

  So far, various adsorbents have been developed in fields such as deodorization and exhaust gas treatment. Activated carbon is a representative example, and is widely used in various industries such as air purification, desulfurization, denitration, and removal of harmful substances by utilizing the excellent adsorption performance of activated carbon. In recent years, the demand for nitrogen has increased for semiconductor manufacturing processes, etc., and as a method for producing such nitrogen, a method of producing nitrogen from air by pressure swing adsorption method or temperature swing adsorption method using molecular sieve charcoal is used. Has been. On the other hand, in recent years, due to increasing awareness of environmental problems, processes and materials for actively collecting carbon dioxide acting as a greenhouse gas have been actively developed. Furthermore, molecular sieve charcoal is applied as a separation or purification material for various gases such as hydrogen separation from methanol cracked gas.

  When separating mixed gas by pressure swing adsorption method or temperature swing adsorption method, generally, molecular sieve charcoal or zeolite is used as the separation adsorbent, and separation is performed by the difference in the equilibrium adsorption amount or adsorption rate. (For example, refer nonpatent literature 1). However, when the mixed gas is separated based on the difference in the amount of equilibrium adsorption, the conventional adsorbents cannot selectively adsorb the gas to be removed, so that the separation factor becomes small, and the apparatus must be enlarged. In addition, when separating the mixed gas based on the difference in adsorption speed, the gas to be removed can be adsorbed depending on the type of gas, but it is necessary to perform adsorption and desorption alternately, and in this case, the apparatus still has to be large. There wasn't.

On the other hand, polymer metal complexes that cause a dynamic structural change by external stimulation have been developed as adsorbents that give better adsorption performance (see Non-Patent Document 2). When a polymer metal complex that causes this new dynamic structural change is used as a gas adsorbent, a unique phenomenon is observed in which gas adsorption does not occur up to a certain pressure, but gas adsorption begins when a certain pressure is exceeded. Has been. In addition, a phenomenon has been observed in which the adsorption start pressure varies depending on the type of gas.
When this phenomenon is applied to, for example, an adsorbent in a pressure swing adsorption type gas separation apparatus, very efficient gas separation is possible. Moreover, the time required for the pressure change can be shortened, which contributes to energy saving. Furthermore, since it can contribute to miniaturization of the gas separation device, it is possible to increase cost competitiveness when selling high-purity gas as a product, of course, even when high-purity gas is used inside its own factory Since the cost required for the equipment that requires high purity gas can be reduced, the manufacturing cost of the final product can be reduced. However, since the polymer metal complex uses a harmful metal element, there is a problem in compatibility with the environment. Moreover, in these complexes containing a metal element having a high specific gravity, there is a concern that the material finally obtained becomes heavy.

All organic polymer materials are more or less molecularly adsorbable and permeable, and their performance varies greatly depending on the type of material and target molecule, so use organic polymer materials to identify gas mixtures. It has long been known that these components can be separated and concentrated. These polymer materials are characterized by lightness, moldability, and productivity. In particular, gas separation by membranes is more energetically advantageous than other separation methods, and is actively applied in various industrial fields because of its features such as small size and light weight, simple mechanism, and maintenance-free characteristics. Yes.
Particularly in recent years, organic polymer materials have attracted attention from the viewpoints of resource saving, energy saving, and recovery of useful gases. For example, separation of air into oxygen and nitrogen, separation and recovery of hydrogen from off-gas in the platform method, separation and recovery of hydrogen during ammonia synthesis, recovery of carbon dioxide from exhaust gas from thermal power generation and garbage incineration, and nitrogen oxides And removal of sulfur oxides, recovery of carbon dioxide from oilfield off-gas, removal of acidic gases such as carbon dioxide and hydrogen sulfide from natural gas, and separation and recovery of helium.

From such a viewpoint, various polymer materials have been studied. Among these, poly-substituted acetylene is known to exhibit unique properties due to its unique structure. It is known that poly-substituted acetylene has a rigid main chain structure compared to a vinyl polymer and exhibits high gas permeation performance due to the presence of a bulky substituent (for example, Non-Patent Document 3). Among them, poly-substituted acetylenes such as poly (diphenylacetylene) are known to have high material permeability, selective permeability and excellent thermal stability (for example, Patent Document 1).
However, in these poly-substituted acetylenes obtained by using tantalum pentachloride (TaCl ₅ ) as a catalyst and tetrabutyltin (n-Bu ₄ Sn) as a promoter, analysis results on geometrical isomerism and higher order structure of the obtained polymer The details are unknown, and the adsorption and separation performance of carbon dioxide is not described.
On the other hand, from the polymerization reaction mechanism, it is inferred that the polymer is a mixture of a cis type and a trans type and contains a lot of amorphous (non-patent document 4). Such poly-substituted acetylenes have a distribution in the size and volume of the molecular gaps that contribute to gas permeability, which is disadvantageous for developing high selective adsorption and selective permeation performance. In addition, there is a concern that the property may change over time due to contact with gas molecules involved in adsorption / permeation. Furthermore, it is difficult to industrially synthesize poly (diphenylacetylene) s having a complicated structure in large quantities.
For this reason, there is a demand for a polymer material that is more stable over time, has higher separation performance, and can be industrially mass-produced.

On the other hand, when a substituted acetylene such as p-methylphenylacetylene is polymerized using a rhodium (Rh) complex as a polymerization catalyst, the polymerization proceeds stereoregularly, and the double bond in the main chain is a cis-type poly It is known that substituted acetylene can be obtained (for example, Non-Patent Document 5). The cis-type poly-substituted acetylene in which the double bond of the main chain thus obtained forms a helical structure.
In Patent Document 2, an Rh catalyst having a thiol group is immobilized on a gold substrate by a chemical bond, and a helical substituted polyacetylene structure in which a cis-type polyacetylene in which a double bond of a main chain is arranged vertically on the substrate is arranged. A gas separation membrane has been reported. Orienting molecules with a helical structure in one direction is considered to be one means for effectively utilizing the function. However, in such a structure whose one surface is a metal substrate, it is presumed that it is difficult for gas molecules to permeate perpendicularly to the film surface. It is known that a very small gas molecule such as hydrogen dissolves slightly against a metal such as Pd. However, if the gas molecule has a size as large as carbon dioxide, it can penetrate the gold substrate. It is even more difficult. On the other hand, when gas molecules are adsorbed, almost half of the functional surface performing the adsorption function is lost, and there remains a problem in terms of adsorption efficiency. Further, it is difficult to peel off the poly-substituted acetylene chemically bonded on the gold substrate from the substrate without destroying the structure. Furthermore, it is extremely difficult to industrially manufacture a structure manufactured through such a complicated process in large quantities at low cost.

JP 2002-322293 A JP 2008-2222796 A

Supervised by Satoshi Takeuchi, “The latest adsorption technology handbook” 1st edition, NTS Corporation, p. 84-163 (1999) Ryotaro Matsuda et al., Petrotec, Vol. 26, No. 2, p. 97-104 (2003) T.A. Masuda, et. al. , J .; Am. Chem. Soc. , Vol. 105, p. 7473-7474, (1983) Toshio Masuda et al., Synthetic Organic Chemistry, Vol. 43, No. 8, p. 744-752 (1985) Tabata Masayoshi et al., Polymer, Vol. 55, No. 12, p. 938-941 (2006)

  This invention is made | formed in view of the above situations, and the subject of this invention was superior to the conventional carbon dioxide adsorbent which has the selective adsorption characteristic superior to the past, and this adsorbent. The object is to provide a separation or purification material having carbon dioxide separation ability.

The present inventors diligently studied to solve the above problems, and propiolic acid containing a crystal structure in which the double bond of the main chain is a cis type and forms a helical structure, and these helical structures are aggregated. It has been found that the above object can be achieved by a polymer formed from (acetylene carboxylic acid) or a derivative thereof, and the present invention has been completed.
According to the present invention, the following is provided.
(1) General formula (I)

[Wherein n is an integer of 10 to 100,000. R is (wherein, M represents a hydrogen atom or a lithium, represents a sodium or potassium) alkyl or M having a carbon number of 1 to 5 represent a]
A carbon dioxide adsorbent comprising a cis-type polymer with a double bond in the main chain formed from propiolic acid or a derivative thereof represented by:
(2) The carbon dioxide adsorbent according to (1) above, wherein the polymer having a cis-type double bond in the main chain formed from the propiolic acid or derivative thereof is poly (methylpropiolate),
(3) The carbon dioxide adsorbent according to the above (1), wherein the polymer having a cis-type double bond in the main chain formed from propiolic acid or a derivative thereof is poly (ethylpropiolate),
(4) The carbon dioxide adsorbent according to the above (1), wherein the polymer having a cis-type double bond of the main chain formed from the propiolic acid or derivative thereof is poly (n-butylpropiolate),
( 5 ) The carbon dioxide adsorbent according to (1), wherein n is 100 to 5,000,
( 6 ) The carbon dioxide adsorbent according to the above (1), which is for adsorbing carbon dioxide in helium, hydrogen, oxygen, nitrogen, carbon monoxide, hydrocarbon having 1 to 5 carbon atoms, or a mixture thereof.
( 7 ) The carbon dioxide adsorbent according to (1) above, wherein the double bond of the main chain formed from propiolic acid or a derivative thereof polymerized using a group 8-10 metal compound as a catalyst is a cis-type polymer, 8 ) Provided is a separation or purification material comprising the carbon dioxide adsorbing material according to any one of (1) to ( 7 ) above.

  Since the carbon dioxide adsorbing material and the separation or purification material of the present invention contain a crystal in which the double bond of the main chain is a cis type and forms a helical structure, and these helical structures are aggregated, High stability. In addition, side chain substituents having carbonyl groups located in the vicinity are highly arranged, and carbon dioxide mixed in helium, hydrogen, oxygen, nitrogen, carbon monoxide, various hydrocarbons and mixtures thereof is selected. Therefore, it can be suitably used for purification of natural gas, methane fermentation gas, exhaust gas from thermal power generation and garbage incineration, carbon dioxide separation and recovery from off-gas of oil fields, and the like.

ADVANTAGE OF THE INVENTION According to this invention, the adsorption material which can selectively adsorb | suck carbon dioxide, and the separation or refinement | purification material which consists of them can be provided. The present invention is described in detail below.
The carbon dioxide adsorbing material of the present invention comprises a polymer formed from propiolic acid represented by the general formula (I) or a derivative thereof. Hereinafter, a polymer formed from propiolic acid or a derivative thereof is simply referred to as a polymer.

The polymer contains a crystal in which the double bond of the main chain is a cis type and forms a helical structure, and these helical structures are aggregated.
The average degree of polymerization of the polymer can be calculated, for example, based on a calibration curve obtained from a polystyrene standard substance by measurement using size exclusion chromatography (SEC).
The primary structure of the polymer can be measured by, for example, ¹ H- and ¹³ C-NMR.
The higher order structure of the polymer can be measured, for example, by a symmetric reflection method (WAXD analysis) using an X-ray diffractometer.

[Average polymerization degree of polymer]
The average degree of polymerization n in the general formula (I) is 10 to 100,000, preferably 100 to 100,000, and more preferably n is an integer of 100 to 10,000. When n is 10 or more, the molded product obtained from the polymer is more excellent in mechanical strength, and when it is 100 or more, the moldability is more preferable. On the other hand, considering the production cost and molding cost of the polymer, it is preferably 10,000 or less. The number average molecular weight of the polymer having n of 10 to 100,000 is about 1,000 to 30,000,000. Under the reaction (polymerization) conditions described later, when the reaction temperature is lowered, the reaction time is shortened, or the concentration of propiolic acid or its derivative is lowered, the number average molecular weight of the obtained polymer is lowered.

[Substituent R of Polymer]
In the above general formula (I), R is an optionally substituted alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and optionally having 6 to 14 carbon atoms, preferably Represents an aryl group having 6 to 10 carbon atoms, a heterocyclic group having 4 to 15 carbon atoms, preferably 4 to 7 carbon atoms, and M (wherein M represents a hydrogen atom or a monovalent metal).

[C1-C10 alkyl group]
In the above general formula, as the alkyl group having 1 to 10 carbon atoms represented by R, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, cyclopropyl group, Examples include linear, branched or cyclic alkyl groups such as cyclopentyl group, cyclohexyl group, and cyclooctyl group. Among them, carbon dioxide adsorbents obtained and adsorption capacity of separation or purification materials, viewpoints of easy availability of raw materials Is preferably a methyl group. From the viewpoint of moldability, an ethyl group is preferable.
These alkyl groups may have a substituent. Examples of the substituent include aryl groups such as a phenyl group, a naphthyl group, an anthracenyl group, a naphthacenyl group, and a pentacenyl group; a pyridyl group, a thienyl group, and a furyl group. Heterocyclic groups such as pyrrolyl group; methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butoxy group, n-hexyl group, cyclohexyloxy group, n-octyloxy group, n-decyloxy group, etc. Alkoxy groups such as methylthio, ethylthio, propylthio, and butylthio; arylthio groups such as phenylthio and naphthylthio; trisubstituted silyloxy such as tert-butyldimethylsilyloxy and tert-butyldiphenylsilyloxy Group: acetoxy group, pro An acyloxy group such as a noyloxy group, a butanoyloxy group, a pivaloyloxy group and a benzoyloxy group; an alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group and an n-butoxycarbonyl group; a methylsulfoxide group, an ethylsulfoxide group; Sulfoxide groups such as phenyl sulfoxide groups; sulfonic acid ester groups such as methyl sulfonyloxy groups, ethyl sulfonyloxy groups, phenyl sulfonyloxy groups, methoxy sulfonyl groups, ethoxy sulfonyl groups, and phenyloxy sulfonyl groups; dimethylamino groups, diphenylamino Group, primary or secondary amino group such as methylphenylamino group, methylamino group, ethylamino group; acetyl group, benzoyl group, benzenesulfonyl group, tert-but An amino group optionally substituted with an alkyl group or aryl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, phenyl, etc. Group; hydroxyl group; cyano group; nitro group; halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom.

[Aryl group having 6 to 14 carbon atoms]
In the general formula (I), examples of the aryl group having 6 to 14 carbon atoms represented by R include aromatic hydrocarbon groups such as phenyl group, naphthyl group, anthracenyl group, and phenanthryl group. From the viewpoint of easiness, it is preferably a phenyl group. In these, the double bond of the main chain is arranged outside the helical structure formed by the cis-type polymer, and contributes to the stabilization of the helical structure by forming π-π stacking between the side chains.

[C4-C7 heterocyclic group]
In the general formula (I), the heterocyclic group having 4 to 7 carbon atoms represented by R is a heterocyclic group such as a furyl group, a pyrrolyl group, a thienyl group, a pyrazyl group, a pyridyl group, an indolyl group, or a quinolyl group. Etc. Among them, the double bond of the main chain is arranged outside the helical structure formed by the cis-type polymer, and π-π stacking is formed between the side chains, contributing to the stabilization of the helical structure. From the viewpoint of enhancing selectivity by affinity, a pyrrolyl group, a pyrazyl group, and a pyridyl group are preferable.

  These aryl groups and heterocyclic groups may have a substituent, such as a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group. Linear, branched or cyclic alkyl groups such as cyclopropyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group; vinyl group, allyl group, crotyl group, prenyl group, 7-octenyl group, cyclohexenyl group, etc. Alkenyl group; alkynyl group such as ethynyl group, propynyl group, propargyl group, phenylethynyl group; methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butoxy group, n-hexyl group, cyclohexyloxy group, alkoxy groups such as an n-octyloxy group and an n-decyloxy group; Alkylthio groups such as tilthio group, ethylthio group, propylthio group and butylthio group; arylthio groups such as phenylthio group and naphthylthio group; trisubstituted silyloxy groups such as tert-butyldimethylsilyloxy group and tert-butyldiphenylsilyloxy group; acetoxy group , Propanoyloxy group, butanoyloxy group, pivaloyloxy group, benzoyloxy group and other acyloxy groups; methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group and other alkoxycarbonyl groups; methyl sulfoxide group, ethyl sulfone group Sulfoxide groups such as oxide group and phenyl sulfoxide group; methyl sulfonyloxy group, ethyl sulfonyloxy group, phenyl sulfonyloxy group, methoxy sulfonyl group, ethoxys Sulfonic acid ester groups such as phonyl group and phenyloxysulfonyl group; primary or secondary amino groups such as dimethylamino group, diphenylamino group, methylphenylamino group, methylamino group and ethylamino group; acetyl group and benzoyl group An alkyl group or an aryl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, or a phenyl group, which is substituted with a benzenesulfonyl group or a tert-butoxycarbonyl group. An optionally substituted amino group; a hydroxyl group; a cyano group; a nitro group; a halogen atom such as a chlorine atom, a bromine atom, an iodine atom, or a fluorine atom;

[M]
In the general formula (I), M represented by R (wherein M represents a hydrogen atom or a monovalent metal) can be taken as an alkali metal such as lithium, sodium, potassium, and copper (monovalent). And transition metals such as silver. Of these, alkali metals are preferable.

[Production method]
In the present invention, as a method for obtaining the polymer represented by the general formula (I), the polymer is synthesized by the process represented by the following chemical reaction formula.

Details of the chemical reaction are described below.
[Solvent for polymerization]
In the present invention, polymerization of propiolic acid such as methylpropiolate or ethylpropiolate or a derivative thereof is usually carried out in an organic solvent.
Examples of the organic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, isobutyl alcohol, isopentyl alcohol, and neopentyl alcohol; (mono, di, tri) methylamine, (same) ethylamine, (same) propylamine, ( The same) alkylamines such as butylamine; amino alcohols such as ethanolamine; dimethyl ether, ethyl methyl ether, diethyl ether, dipropyl ether, butyl methyl ether, tert-butyl methyl ether, dibutyl ether, ethyl phenyl ether, diphenyl ether, tetrahydrofuran , Ethers such as 1,4-dioxane; acetone, ethyl methyl ketone, methyl propyl ketone, diethyl ketone, ethyl propyl ketone, dipro Ketones such as ruketone; hydrocarbons such as heptane, pentane, hexane, octane, cyclohexane; halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethane, trichloroethane, chlorobenzene; Nitriles such as acetonitrile, propionitrile and benzonitrile; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene and ethylbenzene.
Among these organic solvents, it is preferable to use a highly polar organic solvent such as alcohol, amine and amino alcohol from the viewpoint of reaction rate. These organic solvents may be used alone or in combination of two or more.

When the organic solvent is used, the amount of the organic solvent used is not particularly limited, but is generally 1 to 95% by mass, preferably 70 to 95% by mass in the entire propiolic acid or derivative thereof and the organic solvent mixed solution. It is a range.
When the amount of the organic solvent used is 1% by mass or more, the viscosity of the mixed solution is lowered to enable efficient stirring, and when the amount is 95% by mass or less, a practical reaction rate is maintained. be able to.

[Polymerization catalyst]
In the present invention, when polymerizing propiolic acid or a derivative thereof such as methyl propiolate or ethyl propiolate, it is preferable to use a catalyst in order to make the reaction proceed smoothly. The catalyst is a group 8-10 metal compound. Is preferably used.
Examples of the preferably used Group 8-10 metal compound include a rhodium complex, a palladium complex, an iridium complex, and a platinum complex.
Examples of rhodium complexes include chlorotris (triphenylphosphine) rhodium, acetylacetonatobis (ethylene) rhodium, acetylacetonatobis (cyclooctene) rhodium, acetylacetonato (1,5-cyclooctadiene) rhodium, 5-cyclooctadiene) bis (triphenylphosphine) rhodium hexafluorophosphate, (norbornadiene) tris (triphenylphosphine) rhodium hexafluorophosphate, bis (1,5-cyclooctadiene) rhodium trifluoromethanesulfonate, bis (norbornadiene) Rhodium tetrafluoroborate, chlorobis (ethylene) rhodium dimer, chlorobis (cyclooctene) rhodium dimer, chloro (1,5-cyclooctadiene) Ethidium dimer, chloro (norbornadiene) rhodium dimer, chloro (dicyclopentadienyl) rhodium dimer, chloro (tetrafluorobenzoylene Bale Ren) rhodium dimer and the like.
Examples of the palladium complex include dichloro (1,5-cyclooctadiene) palladium. Examples of iridium complexes include acetylacetonato (1,5-cyclooctadiene) iridium, bis (1,5-cyclooctadiene) iridium tetrafluoroborate, chlorobis (cyclooctene) iridium dimer, chloro (1,5-cycloocta Diene) iridium dimer and the like.
Examples of the platinum complex include dichloro (1,5-cyclooctadiene) platinum and dichloro (dicyclopentadienyl) platinum.
Among these, chloro (1,5-cyclooctadiene) rhodium dimer, chloro (norbornadiene) rhodium dimer, and chloro (tetrafluorobenzovalerene) rhodium dimer are preferable. From the viewpoint of polymerization activity and industrial availability, chloro ( Norbornadiene) rhodium dimer is more preferred.

  The amount of the catalyst used is preferably in the range of 0.000001 to 10 mol in terms of metal atom per liter of the reaction (polymerization) mixed solution (propiolic acid or a derivative thereof and the organic solvent). A range of ˜1 mol is more preferred. When the amount of the catalyst used is less than 0.000001 mol per liter of the reaction (polymerization) mixture in terms of metal atoms, the reaction rate tends to be extremely slow, and even if the amount exceeds 10 mol, an effect commensurate with it is obtained. It only increases the cost of the catalyst.

[Copolymerization catalyst]
In the present invention, for the polymerization of propiolic acid such as methylpropiolate and ethylpropiolate or a derivative thereof, triethylamine, tributylamine, tri-n-octylamine is optionally used to increase the activity of the reaction. N, N, N ′, N′-tetramethyl-1,2-diaminoethane, N, N, N ′, N′-tetramethyl-1,3-diaminopropane, N, N, N ′, N ′ -Polymerization of tetramethyl-1,4-diaminobutane, N, N-diethylethanolamine, triethanolamine, N-methylpiperidine, N-methylpyrrolidine, N-methylmorpholine, pyridine, picoline, lutidine, collidine, quinoline, etc. It may be carried out in the presence of a promoter for use.

  When the cocatalyst is used, it is preferably added in an amount of usually 1 mol or more per 1 mol of the metal of the catalyst, and can also be used as an organic solvent for the reaction.

[Polymerization conditions]
In the present invention, the reaction temperature when polymerizing propiolic acid such as methyl propiolate or ethyl propiolate or a derivative thereof is preferably in the range of −60 to 100 ° C., and in the range of 0 to 40 ° C. More preferably. By setting the reaction temperature to −60 ° C. or higher, the reaction proceeds within an appropriate time, and by setting it to 100 ° C. or lower, side reactions such as isomerization from the cis form to the trans form can be suppressed.
The reaction time in the polymerization of propiolic acid or a derivative thereof is usually in the range of 1 minute to 48 hours, and preferably in the range of 0.5 to 10 hours from the viewpoint of production efficiency. Usually, it is preferable to carry out the reaction for a long time when the reaction temperature is low and for a short time when the reaction temperature is high.
The reaction in the polymerization of propiolic acid or a derivative thereof is usually performed under normal pressure.
The reaction is usually carried out according to the following procedure.
First, a mixed solution 1 in which propiolic acid or a derivative thereof is dissolved in an organic solvent is prepared. Separately, a mixed liquid 2 in which a catalyst such as a group 8-10 metal compound and an additive such as triethylamine are dissolved in the same organic solvent is prepared. Subsequently, the liquid mixture 1 and the liquid mixture 2 are mixed, stirred while being kept at a predetermined reaction temperature, and reacted for a predetermined time to obtain a reaction liquid containing a polymer.

  In this polymerization, it is preferable to use a poor solvent having low solubility of the resulting polymer, for example, alcohol, amine, acetonitrile, ether, acetate, acetone, water or n-hexane. Alternatively, the propiolic acid or its derivative may be polymerized at room temperature for several hours using a mixed solvent such as alcohol containing amine, toluene, chloroform, dimethylformamide, dimethyl sulfoxide or supercritical liquid carbon dioxide. Since the polymer polymerized in this way aggregates and precipitates in a solvent, a porous body or powder is obtained.

[Polymer isolation and purification]
In the present invention, the polymer can be isolated and purified by a general technique from the reaction solution obtained in the polymerization step of propiolic acid or its derivative such as methylpropiolate or ethylpropiolate. For example, the polymer can be obtained by adding the obtained reaction solution to a poor solvent such as methanol or water to precipitate the polymer, separating the solution by filtration, and drying. If necessary, the polymer can be subjected to a reprecipitation treatment, or a remaining solvent can be removed using a poor solvent and a Soxhlet extractor.

[Organic solvent vapor treatment]
The polymer used as the carbon dioxide adsorbing material of the present invention can be used by changing the helical structure pitch and crystallinity by treating with an organic solvent vapor as necessary. The organic solvent to be subjected to the organic solvent vapor treatment is not particularly limited as long as it changes the helical structure pitch and crystallinity of the polymer, but the organic solvent (alcohol, amine, amino acid) having a solubility parameter difference of 10 to 15 Alcohol, hydrocarbon, etc.), particularly n-hexane is particularly preferred from the viewpoint of processing efficiency. Here, the solubility parameter of the polymer can be calculated according to the Bicerano method described in Reference Document 1 below. On the other hand, the solubility parameter described in Reference Document 2 below can be used as the solubility parameter of the organic solvent vapor.
Reference 1: Prediction of polymer properties. , Marcel Dekker Inc. , New York (1993)
Reference 2: A. F. M.M. Barton, Chem. Rev. , Vol. 75, p. 731-753 (1975)
By exposing the polymer under these solvent vapors, the helical structure pitch is decreased and the crystallinity is increased, and the size and regularity of the molecular gaps are changed to obtain the carbon dioxide adsorbent having the desired adsorption performance. be able to.
As a specific treatment method, under an inert gas atmosphere or an air atmosphere, the polymer is exposed to a stream of organic solvent vapor, or the polymer is added to a sealed container, and the system is in a reduced pressure state. It is preferable to carry out by releasing the reduced pressure with an organic solvent vapor. For example, when the polymer is in a powder form, an atmosphere of an organic solvent vapor may be formed in an inert gas atmosphere or an air atmosphere in the tower, and the powder of the polymer may be sprayed from the top. The organic solvent vapor may be circulated in the laminated state. When processing in the form of a film, the organic solvent vapor may be circulated in a state of being wound together with a net-like spacer.
Next, specific conditions for the organic solvent vapor treatment will be described. The partial pressure of the organic solvent vapor is equal to or lower than the saturated vapor pressure of the organic solvent vapor under the processing conditions, but is preferably closer to the saturated vapor pressure from the viewpoint of the processing speed. The treatment temperature is preferably in the range of -20 to 100 ° C, more preferably in the range of 0 to 40 ° C. The treatment time is preferably in the range of 1 second to 20 hours, and more preferably in the range of 1 minute to 10 hours.

[Heat treatment]
The polymer used as the carbon dioxide adsorbent of the present invention is subjected to heat treatment as necessary, thereby causing a decrease in helical structure pitch and an increase in crystallinity, changing the size and regularity of molecular gaps, and the desired adsorption. A carbon dioxide adsorbent having performance can be obtained.
As a specific treatment method, it is preferable to heat and hold the polymer at a predetermined temperature in an inert gas atmosphere or an air atmosphere.
Next, specific conditions for the solvent treatment will be described. A preferable heat treatment temperature is 50 to 100 ° C. By setting the temperature to 50 ° C. or higher, the pitch and crystallinity of the helical structure can be changed efficiently. By setting the temperature to 100 ° C. or lower, the main chain skeleton is isomerized from the cis type to the trans type, and the helical structure and crystal Can be prevented from collapsing.

[Shape of carbon dioxide adsorbent]
The shape of the carbon dioxide adsorbent of the present invention is not particularly limited and may be any molded body that can be produced using a polymer. For example, a film, a sheet, a plate, a pipe, a tube, a rod-shaped body, a granular body, a powder , Various deformed shapes, fibers, hollow fibers, woven fabrics, knitted fabrics, non-woven fabrics and the like.
In particular, from the viewpoint of efficiently adsorbing carbon dioxide, the larger the surface area of the carbon dioxide adsorbent, the more advantageous, and more preferably in the form of a powder. When this material is used as a separation membrane, it is preferably a film from the viewpoint of gas molecule permeability, selectivity, and processing efficiency, and more preferably a hollow fiber from the viewpoint of processing efficiency.

[Powder]
When the polymer used as the carbon dioxide adsorbent of the present invention is used in the form of powder, it is present in helium, hydrogen, oxygen, nitrogen, carbon monoxide, hydrocarbons having 1 to 5 carbon atoms and mixtures thereof. It can be used as a powdery adsorbent that can adsorb carbon dioxide selectively and efficiently.
As a method for forming a powdered polymer, a polymerization solvent for polymerizing propiolic acid or a derivative thereof is a solvent that is a good solvent for propiolic acid or a derivative thereof and a poor solvent for a polymer. Thus, precipitation occurs simultaneously with the production of the polymer, and a powdery polymer can be obtained.
Moreover, a powdered polymer can also be obtained by dissolving various produced polymers in a good solvent and dropping them in a poor solvent. In this case, it is possible to control the particle size of the powdered polymer to be precipitated by the concentration of the polymer solution and the stirring speed of the poor solvent. By reducing the concentration of the solution and increasing the stirring speed, a powdery polymer having a small particle size can be obtained.

[the film]
When the polymer used as the carbon dioxide adsorbing material of the present invention is used in the form of a film, it can be used as a film capable of selectively adsorbing carbon dioxide. As a method for forming a film, a liquid organic polymer composition is prepared by dispersing or dissolving the carbon dioxide adsorbing material of the present invention in an appropriate solvent, and the liquid organic polymer composition is used as a peelable substrate. Or it can manufacture by employ | adopting the method of drying and removing a solvent after apply | coating on a support body. Examples of the solvent for dissolving the carbon dioxide adsorbent of the present invention include chloroform, dichloromethane, tetrahydrofuran and the like.
The method of applying the carbon dioxide adsorbent of the present invention to the releasable substrate or support is not particularly limited, and any conventionally known coating method using a liquid coating material is adopted. For example, dip coating method, spray coating method, spinner coating method, bead coating method, wire bar coating method, blade coating method, roller coating method, curtain coating method, slit die coater method, gravure coater method, slit reverse coater method Coating methods such as a micro gravure method and a comma coater method can be employed.

[Support]
The carbon dioxide adsorbent of the present invention can be used as it is, but if necessary, natural or synthetic such as cellulose acetate, polyamide, polyester, polycarbonate, polysulfone, polyethersulfone, polyolefin, polytetrafluoroethylene derivative or paper. It may be combined with fibers or inorganic fibers such as glass or alumina. Also. Examples of the shape of the carbon dioxide adsorbent include a bulk body, a woven fabric, a nonwoven fabric, and a film.

[Additive]
As long as the carbon dioxide adsorbing material of the present invention is within a range that does not impair the effects of the present invention, an antioxidant, an antifreezing agent, a pH adjusting agent, a concealing agent, a colorant, an oil agent, a flame retardant, and the like as necessary. 1 type or 2 types or more of the additive of a near-infrared absorptive compound, a ultraviolet absorber, a color tone correction agent, dye, antioxidant, and other special function agents.

[Target gas]
The carbon dioxide adsorbing material of the present invention made of a polymer selectively adsorbs carbon dioxide mixed in various gases. In particular, helium, hydrogen, oxygen, nitrogen, carbon monoxide, carbon number 1 It is effective for selectively adsorbing carbon dioxide mixed in ˜5 hydrocarbons or a mixture thereof.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited at all by them. Analysis and evaluation in the following examples and comparative examples were performed as follows.

(1) Confirmation of polymer It measured using the Fourier-transform-type infrared spectrophotometer (FT-IR), and the production | generation of the polymer was confirmed from presence of a chemical bond. Details of the measurement conditions are shown below.
<Analysis conditions>
Apparatus: Fourier transform infrared spectrophotometer JIR-5500 [manufactured by JEOL Ltd.]
Mode: Attenuated total reflection (ATR) method Integration number: 128 times (2) Molecular weight measurement of polymer Measurement was performed using size exclusion chromatography (SEC), and the molecular weight was calculated as polystyrene equivalent. Details of the measurement conditions are shown below.
<Analysis conditions>
Apparatus: High performance liquid chromatography LC-10 [manufactured by Shimadzu Corporation]
Two columns: K-806L (made by Showa Denko KK) connected (column temperature: 40 ° C.)
Mobile phase: Chloroform (for high performance liquid chromatography) [Wako Pure Chemical Industries, Ltd.]
Flow rate: 1.0 ml / min Detector: RI
Filtration: filter with a pore size of 0.45 μm Concentration: 0.5 mg / ml Injection volume: 55 μL
Standard: Polystyrene standard kit [Varian, Inc. Made)
(3) Molecular structure of the polymer:
[Solution ¹ H-NMR]
When the obtained polymer was dissolved in chloroform, solution ¹ H-NMR (nuclear magnetic resonance) measurement was performed, and the structure was identified from the chemical shift value when tetramethylsilane (TMS) was used as an internal standard substance.
<Analysis conditions>
Apparatus: 270 MHz superconducting nuclear magnetic resonance apparatus GSX-270 [manufactured by JEOL Ltd.]
Solvent: deuterated chloroform containing 0.05 v / v% TMS [Cambridge Island Laboratories, Inc. Made)
Concentration: 30 mg / ml Temperature: 25 ° C
Integration count: 128 times [Solid state ¹³ C-NMR (CP / MAS method)]
When the obtained polymer did not dissolve in chloroform, solid ¹³ C-NMR measurement was performed, and the structure was identified from the chemical shift value when glycine was used as the second reference substance.
<Analysis conditions>
Apparatus: 300 MHz superconducting nuclear magnetic resonance apparatus AV300 [VARIAN, Inc. Made)
Temperature: 25 ° C
Integration count: 12,800 times (4) Crystal structure of polymer:
Using an X-ray diffractometer, the range of diffraction angle (2θ) = 2 to 40 ° was scanned at a scanning speed of 0.6 ° / min and measured by a symmetric reflection method (WAXD analysis). Details of the measurement conditions are shown below.
<Analysis conditions>
Apparatus: Rotating anti-cathode X-ray diffractometer RINT2400 [manufactured by Rigaku Corporation]
X-ray generator: enclosed tube X-ray generator X-ray source: Cu 40 kV 40 mA
Goniometer: Sample horizontal goniometer Detector: Scintillation counter Step width: 0.04 °
Slit: Divergent slit = 1 °, Light receiving slit = 0.15 mm, Scattering slit = 1 °
Collimator: None Sample: Filled glass sample plate (5) Gas adsorption amount measurement The gas adsorption amount measurement is specifically described below. In the following examples and test examples, helium is represented as He, hydrogen as H ₂ , carbon dioxide as CO ₂ , and methane as CH ₄ .
<Analysis conditions>
Pretreatment of measurement sample: Drying under reduced pressure with a rotary pump at room temperature for 12 hours (degree of ultimate vacuum: 5 Pa)
Adsorbate: Any pure gas of CO ₂ , CH ₄ , H ₂ , He, or CO ₂ / CH ₄ mixed gas [CO ₂ / CH ₄ (volume ratio) = 75/25, 50/50, 25/75 ]
Adsorption equilibrium time: 60 minutes Adsorption temperature: 273 ° K
Adsorption pressure: 101.3kPa (atmospheric pressure)
Gas blender: SECB-2 [Horiba Estec Co., Ltd.]
Gas chromatography: GC-14B [manufactured by Shimadzu Corporation]
[Gas chromatography analysis conditions]
Column: WG-100 manufactured by GL Sciences Inc.
INJ temperature: 100 ° C
DET temperature: 50 ° C
Column temperature: 50 ° C
Carrier gas: Helium Injection volume: 1 ml Detector: TCD
<Analysis procedure>
Sample pretreatment:
In order to remove unnecessary molecules adsorbed on the measurement sample, a sample weighed in a predetermined amount was sealed in a 20 ml flask and dried under reduced pressure with a rotary pump at room temperature for 12 hours (degree of ultimate vacuum: 5 Pa).
Measurement of dead volume:
After sucking atmospheric He gas (He gas is not adsorbed by the sample) until the scale of the syringe reaches 100 ml, set the flask containing the pretreated sample in the apparatus, open the cock on the flask side, The dead volume of the flask was determined from the scale of the syringe. After measuring the dead volume, the rotary pump line was connected and the pressure was reduced for 1 hour to remove the He gas in the flask.
Gas adsorption measurement:
After sucking a predetermined measurement gas (in the case of mixed gas, prepare any mixed gas through a gas blender) until the scale of the syringe reaches 100 ml, open the cock on the flask side until gas adsorption reaches equilibrium Hold for 60 minutes. After 60 minutes, the dead volume of the flask was subtracted from the scale of the syringe to determine the mixed gas adsorption capacity. The composition of the adsorbed gas was calculated from the gas chromatographic analysis value of the residual gas.

[Example 1]
<Synthesis of poly (methylpropiolate)>
Chloro (norbornadiene) rhodium dimer 230 mg (0 mg) dissolved in 20 ml of distilled methanol bubbling nitrogen in a 50 ml three-necked flask equipped with a magnetic stirrer, a nitrogen line and a nitrogen balloon connected by a three-way cock, and a septum 0.5 mmol), and maintained at 40 ° C. in a nitrogen atmosphere. Then, 4.205 g (50 mmol) of methyl propiolate dissolved in 5 ml of distilled methanol bubbled with nitrogen was fed at 0.5 ml / min. did. After the completion of feeding, it was kept at 40 ° C. for 5 hours under a nitrogen atmosphere. After a predetermined time, excess methanol was added to stop the reaction, and after filtration, it was further washed several times with methanol and dried under reduced pressure at room temperature for 12 hours.
The obtained product was subjected to FT-IR measurement, and disappearance of the peak of 2127 cm ⁻¹ (νC≡C), 3280 cm ⁻¹ (νH—C≡) derived from the triple bond of the monomer, and the main chain of the polymer double bonds derived from 1621cm ^-1 (νC = C), it was confirmed that occurrence with a polymer of 2958cm ^-1 (νH-C =) is generated. The obtained polymer was insoluble in various organic solvents, and its number average molecular weight could not be calculated.
Since the obtained polymer was insoluble in various organic solvents, solid ¹³ C-NMR measurement was performed by the CP / MAS method. As a result, 52 ppm (—O C H ₃ ), 128 ppm (= C H— ), 134ppm (= C -) , has a peak attributed respectively 164ppm (C = O), double bond in the main chain was confirmed to be the cis-poly (methyl propiolate) .
Subsequently, as a result of the WAXD analysis, when it is assumed that a diffraction peak appearing at an interplanar spacing d = 8.5Å (2θ = 10.3 °) belongs to the (100) plane of hexagonal crystal, the interplanar spacing d And lattice constant relationship
1 / d ² = 4 (h ² + hk + k ² ) / 3a ² + l ² / c ²
a, c: length of crystal axis [Å]
h, k, l: Miller index [-]
From this, a = 9.8 cm is obtained. Similarly, when it is assumed that the diffraction peak appearing at the interplanar spacing d = 4.8Å (2θ = 18.2 °) belongs to the (200) plane of hexagonal crystal, a / 2 = 5.5Å is obtained. Since the surface was equivalent to the diffraction peak that appeared at an interplanar spacing d = 8.5８ (2θ = 10.3 °), the crystal structure of the obtained polymer was assigned to be a pseudo hexagonal crystal.
<Gas adsorption measurement of poly (methylpropiolate)>
As a result of measuring the pure gas adsorption amount of CO ₂ and CH _{4 for} the obtained poly (methylpropiolate), the adsorption amount at 273 ° K. and atmospheric pressure was CO ₂ = 11.0 ml / g, and CH ₄ was not adsorbed at all.
Next, Table 1 shows the results of measuring the adsorption amount for the CO ₂ / CH ₄ mixed gas.

[Example 2]
<Synthesis of poly (ethylpropiolate)>
The reaction was carried out in the same manner as in Example 1 except that 4.905 g (50 mmol) of ethyl propiolate was used instead of methyl propiolate.
The obtained product was subjected to FT-IR measurement, and disappearance of the peak of 2127 cm ⁻¹ (νC≡C), 3280 cm ⁻¹ (νH—C≡) derived from the triple bond of the monomer, and the main chain of the polymer double bonds derived from 1625cm ^-1 (νC = C), it was confirmed that occurrence with a polymer of 2985cm ^-1 (νH-C =) is generated.
The number average molecular weight of the obtained polymer was 22,000 [degree of polymerization≈224].
Since the resulting polymer is soluble in chloroform, it was dissolved in deuterated chloroform, ¹ H-NMR measurement results of _{performing, 1.23ppm (-CH 2 C H 3} : 3H), 3.97pm (-C H ₂ CH ₃ : 2H) and 6.86 ppm (-C H = C-: 1H), respectively, and the main chain double bond is cis-type poly (ethylpropiolate) It was confirmed that.
Subsequently, as a result of the WAXD analysis, when it is assumed that a diffraction peak appearing at an interplanar spacing d = 10.7 Å (2θ = 8.3 °) belongs to the (100) plane of hexagonal crystal, the interplanar spacing d And lattice constant relationship
1 / d ² = 4 (h ² + hk + k ² ) / 3a ² + l ² / c ²
a, c: length of crystal axis [Å]
h, k, l: Miller index [-]
From this, a = 12.4Å is obtained. Similarly, if it is assumed that the diffraction peak appearing at the interplanar spacing d = 5.6Å (2θ = 15.8 °) is attributed to the hexagonal (200) plane, a / 2 = 6.5Å is obtained. Since the surface was equivalent to the diffraction peak that appeared at an interplanar spacing of d = 10.7 ＝ (2θ = 8.3 °), the crystal structure of the obtained polymer was assigned to be a pseudo hexagonal crystal.
<Measurement of gas adsorption amount of poly (ethyl propiolate)>
As a result of measuring the pure gas adsorption amount of CO ₂ and CH _{4 for} the obtained poly (ethyl propiolate), the adsorption amount at 273 ° K. under atmospheric pressure was CO ₂ = 5.2 ml / g, and CH ₄ was not adsorbed at all.
Next, Table 1 shows the results of measuring the adsorption amount for the CO ₂ / CH ₄ mixed gas.

[Example 3]
<Synthesis of poly (n-butylpropiolate)>
In Example 1, the reaction was conducted in the same manner as in Example 1 except that 6.305 g (50 mmol) of n-butylpropiolate was used instead of methylpropiolate.
The obtained product was subjected to FT-IR measurement, and disappearance of the peak of 2127 cm ⁻¹ (νC≡C), 3280 cm ⁻¹ (νH—C≡) derived from the triple bond of the monomer, and the main chain of the polymer double bonds derived from 1623cm ^-1 (νC = C), it was confirmed that occurrence with a polymer of 2988cm ^-1 (νH-C =) is generated.
The number average molecular weight of the obtained polymer was 32,000 [degree of polymerization≈254].
Since the resulting polymer is soluble in chloroform, it was dissolved in deuterated chloroform, ¹ H-NMR measurement results of _{performing, 0.93ppm (-CH 2 C H 3} : 3H), 1.38pm (-C _{H 2 CH 3: 2H),} 1.59pm (-CH 2 -C H 2 -CH 2 -: 2H), 3.76~3.98ppm (-O-C H 2 -CH 2 -: 2H), 6 Each peak has a peak attributed to .85 ppm (-C H = C-: 1H), and it was confirmed that the double bond of the main chain was cis-type poly (n-butylpropiolate).
Subsequently, as a result of the WAXD analysis, when it is assumed that the diffraction peak appearing at the interplanar spacing d = 12.4． (2θ = 7.1 °) belongs to the (100) plane of the hexagonal crystal, the interplanar spacing d And lattice constant relationship
1 / d ² = 4 (h ² + hk + k ² ) / 3a ² + l ² / c ²
a, c: length of crystal axis [Å]
h, k, l: Miller index [-]
From this, a = 14.3１４ is obtained. Similarly, if it is assumed that the diffraction peak appearing at the interplanar spacing d = 5.6Å (2θ = 15.8 °) is attributed to the hexagonal (200) plane, a / 2 = 6.5Å is obtained. Since the surface was equivalent to the diffraction peak that appeared at an interplanar spacing d = 12.4． (2θ = 7.1 °), the crystal structure of the obtained polymer was assigned as a pseudo hexagonal crystal.
<Measurement of gas adsorption amount of poly (n-butylpropiolate)>
The obtained poly (n-butylpropiolate) was measured for the pure gas adsorption amounts of CO ₂ and CH _4. As a result, the adsorption amount at 273 ° K. and atmospheric pressure was CO ₂ = 2.6. Milliliter / g and CH ₄ was not adsorbed at all.
Next, Table 1 shows the results of measuring the adsorption amount for the CO ₂ / CH ₄ mixed gas.

[Comparative Example 1]
<Synthesis of poly (phenylacetylene)>
In Example 1, the reaction was conducted in the same manner as in Example 1 except that 5.105 g (50 mmol) of phenylacetylene was used instead of methylpropiolate.
The obtained product was subjected to FT-IR measurement, and the disappearance of the peak of 2110 cm ⁻¹ (νC≡C), 3291 cm ⁻¹ (νH—C≡) derived from the triple bond of the monomer, and the polymer main chain double bonds derived from 1597cm ^-1 (νC = C), it was confirmed that occurrence with a polymer of 3020cm ^-1 (νH-C =) is generated. The number average molecular weight of the obtained polymer was 44,200 [degree of polymerization≈433].
Since the obtained polymer is soluble in chloroform, it was dissolved in deuterated chloroform and subjected to ¹ H-NMR measurement. As a result, σ (ppm) = 5.84 ppm (-C H = C-: 1H), 6 .62 to 6.94 pm (—C ₆ H ₅ : 5H), and the main chain double bond was confirmed to be cis-type poly (phenylacetylene).
Subsequently, as a result of the WAXD analysis, when it is assumed that the diffraction peak appearing at the interplanar spacing d = 11.2Å (2θ = 7.9 °) belongs to the (100) plane of the hexagonal crystal, the interplanar spacing d And lattice constant relationship
1 / d ² = 4 (h ² + hk + k ² ) / 3a ² + l ² / c ²
a, c: length of crystal axis [Å]
h, k, l: Miller index [-]
From this, a = 12.8１２ is obtained. Similarly, when it is assumed that the diffraction peak appearing at the interplanar spacing d = 4.6Å (2θ = 19.3 °) is attributed to the hexagonal (200) plane, a / 2 = 5.3Å is obtained. Since the surface was equivalent to the diffraction peak that appeared at an interplanar spacing d = 11.2 ° (2θ = 7.9 °), the crystal structure of the obtained polymer was assigned as a pseudo hexagonal crystal.
<Measurement of gas adsorption amount of poly (phenylacetylene)>
As a result of measuring the pure gas adsorption amount of CO ₂ and CH _{4 for} the obtained poly (phenylacetylene), the adsorption amount at 273 ° K. and atmospheric pressure was CO ₂ = 5.6 ml / g, CH ₄ = 1.8 ml / g.
Next, Table 1 shows the results of measuring the adsorption amount for the CO ₂ / CH ₄ mixed gas.

From the results shown in Table 1, the carbon dioxide adsorbent of the present invention, at different CO ₂ / CH ₄ mixed gas adsorption test composition ratios, it is clear that the adsorption of CO ₂ at an extremely high selectivity.

[Comparative Example 2]
The poly (ethyl propiolate) obtained in Example 2 was measured for the amount of H ₂ pure gas adsorbed. As a result, H ₂ was not adsorbed at 273 ° K. under atmospheric pressure.
From the above results and the CO ₂ pure gas adsorption amount (5.2 ml / g) measured in Example 2, the carbon dioxide adsorbent of the present invention does not adsorb H ₂ in the CO ₂ / H ₂ mixed gas, It was confirmed that only carbon dioxide was selectively adsorbed.

[Comparative Example 3]
The poly (ethyl propiolate) obtained in Example 2 was measured for the amount of pure gas adsorption of He. As a result, no He was adsorbed at 273 ° K. and atmospheric pressure.
From the above results and the CO ₂ pure gas adsorption amount (5.2 ml / g) measured in Example 2, the carbon dioxide adsorbent of the present invention does not adsorb He in the CO ₂ / He mixed gas, and carbon dioxide. Only the selective adsorption was confirmed.

  Since the carbon dioxide adsorbing material and the separation or purification material of the present invention contain a crystal in which the double bond of the main chain is a cis type and forms a helical structure, and these helical structures are aggregated, High stability. Moreover, since the side chain substituent having a carbonyl group is highly arranged and selectively adsorbs carbon dioxide mixed in helium, hydrogen, oxygen, nitrogen, carbon monoxide, various hydrocarbons and mixtures thereof, It can be suitably used for purification of natural gas, methane fermentation gas, exhaust gas from thermal power generation and garbage incineration, carbon dioxide separation and recovery from off-gas of oil fields, and the like.

Claims (8)

Formula (I)

[Wherein n is an integer of 10 to 100,000. R is (wherein, M represents a hydrogen atom or a lithium, represents a sodium or potassium) alkyl or M having a carbon number of 1 to 5 represent a]
A carbon dioxide adsorbent comprising a cis-type polymer having a double bond in the main chain formed from propiolic acid represented by   The carbon dioxide adsorbing material according to claim 1, wherein the polymer having a cis-type double bond in the main chain formed from propiolic acid or a derivative thereof is poly (methylpropiolate).   The carbon dioxide adsorbent according to claim 1, wherein the polymer having a cis-type double bond in the main chain formed from propiolic acid or a derivative thereof is poly (ethylpropiolate). The carbon dioxide adsorbent according to claim 1, wherein the polymer having a cis-type double bond in the main chain formed from propiolic acid or a derivative thereof is poly (n-butylpropiolate).   The carbon dioxide adsorbent according to claim 1, wherein n is 100 to 5,000.   The carbon dioxide adsorbent according to claim 1, which is used for adsorbing carbon dioxide in helium, hydrogen, oxygen, nitrogen, carbon monoxide, hydrocarbons having 1 to 5 carbon atoms or a mixture thereof.   The carbon dioxide adsorbent according to claim 1, wherein the double bond of the main chain formed from propiolic acid or a derivative thereof polymerized using a group 8-10 metal compound as a catalyst is a cis polymer. A separation or purification material comprising the carbon dioxide adsorbent according to any one of claims 1 to 7 .