JP2016202030A - Methods for manufacturing (meth)acrylamide, (meth)acrylamide polymers and production methods thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing high quality (meth)acrylamide by using microbial cells and/or processed microbial cells as a catalyst comprising a nitrile hydratase, and acrylamide polymers having both water-solubility and a higher molecular weight as well as an excellent hue by using the (meth)acrylamide.SOLUTION: Provided herein is a method for producing (meth)acrylamide comprising the steps of: culturing a host cell transformed with a vector comprising a gene encoding a nitrile hydratase; and carrying out hydration reaction of (meth)acrylonitrile of which crotononitrile concentration is 100 ppm or less by the using the microbial cells and/or processed cells of the microorganism comprising the nitrile hydratase. In one method for producing (meth)acrylamide, the nitrile hydratase is derived from the genus Pseudonocardia or Rhodococcus. Also provided is a (meth)acrylamide polymer obtained by homopolymerization of the (meth)acrylamide or copolymerization with an amide compound and at least one kind of copolymerizable unsaturated monomer.SELECTED DRAWING: None

Description

  The present invention provides a method for producing (meth) acrylamide having excellent quality by efficiently hydrating (meth) acrylonitrile using a bacterial cell and / or a treated product thereof as a catalyst, and the (meta) The present invention relates to a (meth) acrylamide polymer obtained by polymerizing acrylamide and a method for producing the polymer.

  As one of the main production methods of amide compounds, a hydration method using a nitrile compound as a raw material is used in many cases, and as an industrial production method of amide compounds such as acrylamide, for example, Raney copper or the like A method of hydrating a nitrile compound such as acrylonitrile using a metal copper catalyst, or a method of hydrating a nitrile compound using a microbial body containing nitrile hydratase and / or a treated product thereof as a catalyst in recent years. Are known.

  The method of using bacterial cells and / or treated products thereof as a catalyst has attracted industrial attention because of high conversion and selectivity of nitrile compounds such as acrylonitrile.

  In order to efficiently produce higher quality acrylamide using the nitrile hydratase-containing cells and / or treated cells thereof as a catalyst, catalytic action of the cells and / or treated cells thereof is effective. It is necessary to remove as much impurities as possible.

  Acrylamide is mainly used as a raw material for acrylamide polymers, but in recent years, acrylamide polymers have been required to have higher quality. For example, there are flocculants in the use of acrylamide polymers, but acrylamide polymers used as flocculants have recently been required to have higher molecular weight while maintaining water solubility in accordance with the demand for improved performance. It has been. In addition, acrylamide polymers have applications such as papermaking additives. However, in order to further improve the quality of the obtained paper, a polymer having a better hue is required as the papermaking additive. Yes.

  As a method for improving the quality of acrylamide obtained by using a bacterial cell containing nitrile hydratase and / or a treated product thereof as a catalyst, or a method for improving the quality of an acrylamide polymer, for example, Patent Document 1 discloses that A method for producing an amide compound in which a nitrile hydratase is allowed to act on a nitrile compound after the concentration of hydrocyanic acid is reduced by a chemical method has been proposed. Patent Document 2 discloses an acrylamide polymer in which acrylonitrile having an oxazole concentration of 5 mg / kg or less and a hydrocyanic acid concentration of 1 mg / kg or less is hydrated by an enzymatic method to form acrylamide, and a monomer containing the acrylamide is polymerized. The manufacturing method of this is proposed. Further, Patent Document 3 proposes a method for producing an amide compound characterized in that, in the method for producing an amide compound from a nitrile compound in an aqueous medium, the benzene concentration in the aqueous medium is 4.0 ppm or less. Yes.

  However, in these conventional techniques, sufficient effects are not always obtained from the viewpoint of efficiently hydrating acrylonitrile by eliminating factors that inhibit the catalytic action of bacterial cells including nitrile hydratase. .

JP 11/123098 pamphlet International Publication No. 2004/090148 Pamphlet JP 2012/029695 pamphlet

  In the efficient production of amide compounds using nitrile hydratase, there is another phenomenon that the amide compound productivity of nitrile hydratase decreases due to other factors that cannot be solved by the prior art. It was rare. In addition, there is still room for improvement from the viewpoint of improving the quality of (meth) acrylamide and (meth) acrylamide polymers.

  An object of the present invention is to produce a (meth) acrylamide having higher efficiency and higher quality using a microbial cell containing nitrile hydratase and / or a treated product thereof as a catalyst, and the (meth) acrylamide. Is to provide a method for producing a (meth) acrylamide polymer excellent in quality, excellent in hue, compatible with both water solubility and high molecular weight.

  The present inventors have conducted intensive research to solve the above problems. As a result, the inventors have found that the above problem can be solved by a method for producing (meth) acrylamide having the following steps, and have reached the present invention.

That is, the present invention is as follows.
[1] Production of (meth) acrylamide characterized by hydrating a (meth) acrylonitrile having a crotononitrile concentration of 100 ppm or less with a microbial cell containing nitrile hydratase and / or a treated product thereof. Method [2] The production method according to [1], wherein the nitrile hydratase is derived from Pseudonocardia or Rhodococcus, [3] The (meth) acrylamide according to [1] is homopolymerized, or (Meth) acrylamide polymer obtained by copolymerization with at least one unsaturated monomer copolymerizable with amide compound [4] (meth) acrylamide as described in [1] above, or amide (Meth) acrylic copolymerized with at least one unsaturated monomer copolymerizable with the compound Method for producing amide-based polymer

  In the present invention, in a reaction using a microbial cell containing nitrile hydratase and / or a treated product thereof as a catalyst, the concentration of crotononitrile in (meth) acrylonitrile is reduced to a specific concentration or less (meta ) Acrylamide can be produced efficiently. In addition, by producing an amide polymer using (meth) acrylamide whose crotononitrile concentration is suppressed by the above-mentioned method, it is excellent in hue, excellent in quality and compatible in water solubility and high molecular weight. A polymer can be obtained.

  Hereinafter, the manufacturing method of (meth) acrylamide of this invention is demonstrated.

[Production method of (meth) acrylamide]
The method for producing (meth) acrylamide of the present invention comprises a step of hydrating a (meth) acrylonitrile having a crotononitrile concentration of 100 ppm or less with a microbial cell containing nitrile hydratase and / or a treated product thereof. Have.

<Bacteria and / or treated cells containing nitrile hydratase>
In the present invention, nitrile hydratase-containing cells and / or treated cells thereof (hereinafter also simply referred to as “cell catalysts”) are catalysts for hydration of (meth) acrylonitrile to (meth) acrylamide. Used as

  Nitrile hydratase refers to an enzyme (protein) having the ability to hydrolyze a nitrile compound to produce a corresponding amide compound (hereinafter also referred to as “nitrile hydratase activity”).

The microbial cell containing nitrile hydratase is not particularly limited as long as it produces nitrile hydratase and retains nitrile hydratase activity in an aqueous solution of a nitrile compound and an amide compound. The nitrile hydratase-producing cells include Nocardia, Corynebacterium, Bacillus, thermophilic Bacillus, Pseudomonas, and Micrococcus. , Rhodococcus genus represented by Rhodochrous species, Acinetobacter genus, Xanthobacter genus, Streptomyces genus, Rhizobium genus, Klebsiella genus, Klebsiella Representative of the genus Enterobacter, Erwinia, Aeromonas, Citrobacter, Achromobacter, Agrobacterium or thermophila Genus Pseudonocardia, Bacteridium, Brevibak Such as cells belonging to the helium (Brevibacterium) genus can be mentioned. These may be used alone or in combination of two or more.
In addition, a transformant in which a nitrile hydratase gene cloned from these bacterial cells is highly expressed in an arbitrary host, and one or more of the constituent amino acids of the nitrile hydratase using other DNA by using recombinant DNA technology And a transformant expressing a mutant nitrile hydratase with further improved amide compound resistance, nitrile compound resistance, and temperature resistance by substitution, deletion, deletion or insertion. In addition, as an arbitrary host mentioned here, Escherichia coli is exemplified as a representative example as described later, but is not particularly limited to Escherichia coli, and is not limited to Escherichia coli, and may belong to the genus Bacillus such as Bacillus subtilis. Other strains such as fungi, yeasts and actinomycetes are also included. As an example of such a case, MT-10822 [This strain is the Institute of Biotechnology, Institute of Industrial Technology, Ministry of International Trade and Industry, 1-3 1-3 Higashi, Tsukuba, Ibaraki, on February 7, 1996 (currently Tsukuba, Ibaraki) City East 1-1-1 Tsukuba Center Chuo No. 6 (National Institute of Technology and Evaluation, Patent Biological Deposit Center) under the accession number FERMBP-5785, based on the Budapest Treaty on the international recognition of deposits of bacterial cells under patent procedures It has been deposited. ].

  Among these bacterial cells, in terms of having a highly active and highly stable nitrile hydratase, cells belonging to the genus Pseudonocardia and the nitrile hydratase gene cloned from the bacterial cells can be used in any host. Highly expressed transformants and transformant transformants expressing mutant nitrile hydratase are preferred. In addition, the said transformant is preferable at the point which raises the stability of nitrile hydratase more and the activity per microbial cell is higher.

  Also preferred are Rhodococcus rhodochrous J-1, which can highly express nitrile hydratase in the cells, and transformants in which the nitrile hydratase gene cloned from the cells is highly expressed in any host. . The microbial cells producing the nitrile hydratase can be prepared by a general method known in the fields of molecular biology, biotechnology, and genetic engineering.

  The recombinant vector according to the present invention contains a gene encoding nitrile hydratase, and can be obtained by linking a gene encoding nitrile hydratase to the vector. The vector is not particularly limited. For example, a gene encoding nitrile hydratase in a commercially available expression plasmid represented by pET-21a (+), pKK223-3, pUC19, pBluescriptKS (+), pBR322, etc. Thus, the expression plasmid of nitrile hydratase can be constructed. The host organism to be used for transformation is not limited as long as the recombinant vector is stable and capable of self-propagation and can express foreign DNA traits. For example, E. coli is a good example. The transformant having the ability to produce nitrile hydratase can be obtained by introducing it into Bacillus subtilis, yeast or the like.

  The microbial cells producing nitrile hydratase as described above may be appropriately cultured and grown by a known method to produce nitrile hydratase. As a medium used in this case, either a synthetic medium or a natural medium can be used as long as it contains a suitable amount of carbon source, nitrogen source, inorganic salts and other nutrients. For example, after inoculating the cells in a normal liquid medium such as LB medium or M9 medium, an appropriate culture temperature (generally 20 ° C. to 50 ° C., but in the case of thermophilic bacteria, 50 ° C. or higher) However, it can also be prepared by culturing. Culturing can be carried out in a liquid medium containing the above-mentioned culture components by using a usual culture method such as shaking culture, aeration and agitation culture, continuous culture or fed-batch culture. The culture temperature of the transformant is preferably 15 to 37 ° C. The culture conditions are not particularly limited, and may be appropriately selected depending on the type of culture and the culture method, as long as the strain can grow and produce nitrile hydratase.

  In the present invention, in order to react the microbial cells producing the above nitrile hydratase with the nitrile compound, various treatments such as collection of cells by centrifugation or the like, and crushing to produce crushed bacterial cells, The microbial cells that have been subjected to any of these treatments are collectively referred to as processed microbial cells.

  The form of the disrupted cell is not particularly limited as long as it contains a nitrile hydratase-producing cell. For example, the culture solution containing the cell itself, the culture solution is centrifuged and separated and recovered. And those obtained by washing the collected cells with physiological saline or the like.

<(Meth) acrylonitrile>
In general, commercially available (meth) acrylonitrile becomes a product through a purification process, but the product contains a small amount of impurities. For example, acrylonitrile is generally produced industrially by an ammoxidation process of propylene, but it is commercially available because a small amount of butene-derived crotononitrile contained in propylene is brought into the acrylonitrile product. The acrylonitrile product contains crotononitrile as an impurity.
Although cis-isomer and trans-isomer exist as isomers in crotononitrile, crotononitrile in the present invention indicates both isomers without distinguishing cis-isomer and trans-isomer.

The crotononitrile concentration contained in (meth) acrylonitrile used in the present invention is 100 ppm or less, preferably 80 ppm or less, more preferably 50 ppm or less. The crotononitrile concentration contained in (meth) acrylonitrile being 100 ppm or less means that the amount of crotononitrile contained in 1 kg of (meth) acrylonitrile is 100 mg or less. When the content of crotononitrile in (meth) acrylonitrile is 100 ppm or less, it can be used for the hydration reaction as it is. When the content of crotononitrile in (meth) acrylonitrile is larger than 100 ppm, (meth) acrylonitrile is purified and crotononitrile is removed. The purification method for removing crotononitrile from (meth) acrylonitrile is not particularly limited, and a known method can be used, and distillation is preferred.
The concentration of crotononitrile contained in (meth) acrylonitrile can be quantified by gas chromatography, high performance liquid chromatography, or the like.

<Water (raw water)>
The raw water is not particularly limited, and purified water such as distilled water or ion exchange water can be used.

<PH regulator>
The pH adjusting agent is used to adjust the pH of the reaction mixture to a suitable range for keeping the activity of the cell catalyst good.
When the pH suitable for the reaction is less than 7, an acid can be used as a pH regulator.

As the acid used as the pH regulator, either an inorganic acid or an organic acid can be used. Examples of the inorganic acid include hydrohalic acid such as hydrogen chloride, hydrogen bromide, hydrogen iodide, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromite, bromite, bromine Examples thereof include halogenated oxo acids such as acid, perbromic acid, hypoiodic acid, iodic acid, iodic acid, and periodic acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, and the like. Examples of the organic acid include carboxylic acid such as formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, crotonic acid, succinic acid, malonic acid, fumaric acid, maleic acid, citric acid, lactic acid, benzoic acid, methanesulfonic acid, Examples include sulfonic acids such as ethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. The acid used as the pH adjusting agent can be used in any state of gas, solid, and liquid, but considering the ease of supply to the reaction vessel, it is preferable to use the acid in the liquid state. The acid in the state is more preferably used as an aqueous solution. In consideration of controllability of pH adjustment of the reaction tank, it is more preferable to use a liquid acid as an aqueous solution. The concentration of the acid when used as an aqueous solution is not particularly limited, but pH adjustment becomes difficult when an aqueous solution with a high concentration is used. Therefore, it is preferably 0.1 wt% or more and 99 wt% or less, more preferably 1 wt% or more and 90 wt%. Hereinafter, it is more preferably 1 wt% or more and 50 wt% or less.
When the pH suitable for the reaction is larger than 7, a base can be used as a pH regulator.

  As the base used as the pH regulator, either an inorganic base or an organic base can be used. Examples of the inorganic base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide, lithium carbonate, and sodium carbonate. Alkali metal carbonates such as potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, alkali metal hydrogen carbonates such as potassium hydrogen carbonate, ammonia and the like. Examples of the organic base include trimethylamine, triethylamine, aniline, pyridine and the like. The base used as the pH regulator can be used in any state of gas, solid, and liquid, but considering the ease of supply to the reaction vessel, it is preferable to use a base in the liquid state. The acid in the state is more preferably used as an aqueous solution. In consideration of controllability of pH adjustment of the reaction tank, it is more preferable to use a liquid base as an aqueous solution. The concentration of the base when used as an aqueous solution is not particularly limited, but pH adjustment becomes difficult when an aqueous solution with a high concentration is used. Therefore, it is preferably 0.1 wt% or more and 99 wt% or less, more preferably 1 wt% or more and 90 wt%. Hereinafter, it is more preferably 1 wt% or more and 50 wt% or less.

<Reaction tank>
As the reaction tank, a single-stage reaction tank composed of one reactor may be used, or a multi-stage reaction tank composed of a plurality of reactors may be used. As the reactor, a tank reactor or a tube reactor may be used. As the tank reactor, a reactor equipped with a stirrer is preferable. When the tank reactor has a stirrer, the stirrer blade of the stirrer can be of any shape, for example, propeller blade, flat paddle blade, pitched paddle blade, flat turbine blade, pitched turbine blade, ribbon blade, anchor blade And full zone wings. One stirring blade may be provided, or a plurality of stirring blades may be provided.
An external circulation line equipped with a circulation pump for returning a part of the reaction mixture to the reaction tank may be installed in the reaction tank.

  When an external circulation line having a pump is installed in the reaction tank, the pump provided in the external circulation line is not particularly limited. For example, a turbo pump such as a centrifugal pump, a tilt pump, or an axial flow pump And positive displacement pumps such as reciprocating pumps and rotary pumps.

  When installing an external circulation line equipped with a pump in the reaction tank, a part of the reaction mixture is taken out from the reaction tank using the pump provided in the external circulation line and reacted via the external circulation line. Returned to the tank. It is preferable that a temperature control device is installed in the external circulation line installed in the reaction tank. As the temperature control device, a heat exchanger is preferably used. Examples of the heat exchanger include multi-tubular cylindrical, spiral tube, spiral plate, plate, and double tube types.

  When installing an external circulation line equipped with a pump in a multistage reaction tank composed of a plurality of reactors, all of the external circulation lines equipped with a pump may be installed in each reactor. It may be installed in only one reactor. In the case of multiple reactors, if the external circulation line equipped with a pump is installed in only one of the reactors, it is installed in the first-stage reactor (the most upstream reactor) It is preferred that

  Using a reaction tank composed of a first-stage tank reactor and a second-stage tube reactor, the reaction liquid taken out from the tank reactor is further reacted in the tube reactor, and the tank reaction A reaction tank in which an external circulation line equipped with a pump is installed in the vessel is more preferable because the conversion rate can be improved.

  The tank reactor and the tube reactor may or may not be equipped with a heat exchanger as long as the nitrile hydratase activity of the bacterial cell catalyst is maintained. In order to control, the reactor preferably comprises a heat exchanger. As the heat exchanger, for example, a multi-tubular cylindrical type, a spiral tube type, a spiral plate type, a plate type, a double pipe type or the like is preferably installed on the external circulation line. The thing of the form directly installed in a reactor, such as a formula and a coil type, is mentioned. When the reactor is a tubular reactor, the reactor itself can be composed of a multi-tubular cylindrical or double-tube heat exchanger.

  As the reaction method, for example, (1) a method in which the reaction is carried out after the whole amount of the cell catalyst, the reaction raw material [(meth) acrylonitrile and raw material water] and the pH regulator are charged into the reaction tank at once (batch reaction), (2 ) After the cell catalyst, reaction raw material [(meth) acrylonitrile and raw water] and a part of the pH regulator are charged into the reaction tank, the remaining cell catalyst, reaction raw material [(meth) acrylonitrile continuously or intermittently And raw water] and a method of reacting by supplying a pH regulator (semi-batch reaction), (3) cell catalyst, reaction raw material ((meth) acrylonitrile and raw water) and pH regulator continuously or intermittently Supply and reaction solution [including cell catalyst, unreacted raw material, pH adjuster and (meth) acrylamide produced. The method of continuously reacting without taking out the whole amount of the reaction solution in the reaction tank (continuous reaction) can be mentioned. Among these, a continuous reaction is preferable because it is easy to industrially produce an amide compound in large quantities and efficiently.

  The reaction is performed in the presence of a cell catalyst. The use form of the cell catalyst is preferably a suspension bed. For example, in the case of continuous reaction, a suspension of the cell catalyst may be prepared and the suspension supplied to the reaction vessel.

  When a multistage reaction tank composed of a plurality of reactors is used as the reaction tank, the structure includes (a) a cell catalyst, reaction raw materials ((meth) acrylonitrile and raw water) and a pH regulator. The reaction solution [including the cell catalyst, the unreacted raw material, the pH adjuster, the produced (meth) acrylamide, etc.] ] To the lower reactor, (b) cell catalyst, reaction raw material ((meth) acrylonitrile and raw water) and pH regulator in two or more reactors (via other reactors) (Without) parallel mode of supplying directly.

  For example, in the case where a continuous reaction is performed using a multistage reaction tank, the supply destination of the cell catalyst, the reaction raw material ((meth) acrylonitrile and raw material water) and the pH adjuster is the first-stage reactor (most upstream). It is not limited only to the (reactor located), The reactor after the 2nd stage (reactor located downstream) may be sufficient.

  Although the reaction tank temperature which is the liquid temperature in a reaction tank is based also on the heat resistance of a microbial cell catalyst, it is normally set to 0-50 degreeC, Preferably it is set to 10-40 degreeC. When the reaction vessel temperature is in the above range, it is preferable in that the nitrile hydratase activity of the bacterial cell catalyst can be maintained well.

  The reaction tank temperature refers to the liquid temperature in the reactor when the reaction tank is composed of only one reactor, and in the case where the reaction tank is composed of a plurality of reactors. Refers to the liquid temperature. The reaction vessel temperature can be measured, for example, by a thermocouple method (eg, K type). The reaction vessel temperature can be measured at an arbitrary location in the reaction vessel, and specifically can be measured at the reaction vessel outlet (reaction liquid outlet).

  The reaction is generally performed under normal pressure, but can also be performed under pressure in order to increase the solubility of (meth) acrylonitrile. The pH in the reaction vessel is not particularly limited as long as it is a suitable range for maintaining the activity of the bacterial cell catalyst, but is preferably in the range of pH 5 to pH 10. When the pH is within the above range, it is preferable in that the nitrile hydratase activity can be maintained well.

  When the reaction tank is composed of only one reactor, the pH of the reaction tank refers to the pH within the reactor, and when the reaction tank is composed of a plurality of reactors, The pH of the The pH of the reaction vessel can be measured by, for example, an indicator method, a hydrogen electrode method, a quinhydrone electrode method, an antimony electrode method, or a glass electrode method. The pH of the reaction vessel can be measured at any place in the reaction vessel, and specifically, can be measured at the reaction vessel outlet (reaction liquid outlet).

<Cell catalyst storage tank>
The cell catalyst storage tank has a catalyst supply pipe that holds a cell catalyst suspension and supplies the cell catalyst suspension to the reaction tank. The cell catalyst storage tank may or may not have a temperature control device, but from the viewpoint of controlling the liquid temperature of the suspension of cell catalyst, It is preferable to have it.

  When the bacterial cell storage tank has a temperature control device, the temperature control apparatus may be provided on an external circulation line that the bacterial cell storage tank may have, or may be provided in the bacterial cell storage tank itself. Examples of the temperature control device in the bacterial cell storage tank include a heat exchanger. As the heat exchanger, for example, an external circulation line of a bacterial cell storage tank such as a multi-tube cylindrical heat exchanger, a spiral tube heat exchanger, a spiral plate heat exchanger, a plate heat exchanger, or a double tube heat exchanger Or a type installed directly in a cell catalyst storage tank such as a jacket type heat exchanger or a coil type heat exchanger.

  The bacterial cell catalyst storage tank may have a stirrer or may not have a stirrer, but it is preferable to have a stirrer from the viewpoint of controlling the liquid temperature of the bacterial cell catalyst. When the cell catalyst storage tank has a stirrer, the stirring blade of the stirrer can be of any shape, for example, propeller blade, flat paddle blade, pitched paddle blade, flat turbine blade, pitched turbine blade, ribbon blade, anchor blade And full zone wings. One stirring blade may be provided, or a plurality of stirring blades may be provided.

<Supply of reaction raw materials>
The raw water supplied to the reaction vessel may be supplied alone to the reaction vessel, or may be supplied to the reaction vessel after mixing with (meth) acrylonitrile. When supplying raw material water to the reaction tank alone, there is no particular restriction on the position of the supply port to the reaction liquid in the reaction tank of the raw water supply pipe, and even if it is installed above the reaction liquid, May be installed.

  The method for supplying raw water when supplying raw water alone to the reaction vessel is not particularly limited, and a known method can be used. As a method for supplying raw material water to the reaction tank, a device having a liquid transport function can be used. For example, a centrifugal pump, a tilting pump or an axial flow pump, a reciprocating pump, a rotary pump, etc. Pumps such as positive displacement pumps and conveyors such as screw conveyors can be used. As a method for supplying the raw water to the reaction tank, the raw water can be supplied without using the equipment having the liquid transport function. When equipment with a liquid transport function is not used, for example, a raw water storage tank for storing raw water is installed at the top of the reaction tank, the raw water storage tank and the reaction tank are connected by a raw water supply pipe, and gravity is used. There is a method of supplying by dropping. Or the method of supplying using the pressure difference of the raw material water storage tank and reaction tank which arise by pressurizing a raw material water storage tank is mentioned.

  There may be one raw water supply pipe for supplying raw water to the reaction tank, or a plurality of raw water supply pipes may be provided for one reaction tank. There is no restriction | limiting in particular in the shape of the supply port of a raw material water supply pipe, Any can be used suitably if it is a shape normally used.

  As a method of mixing raw material water and (meth) acrylonitrile in the case of supplying raw water and (meth) acrylonitrile to the reaction vessel after mixing, a known method can be used, for example, stirring and mixing using a stirring vessel And a method of mixing raw material water and (meth) acrylonitrile in a pipe. In the case of using a stirring tank, the shape of the stirring tank is not particularly limited, but a cylindrical stirring tank is generally used, and it can be used in any case of a vertical cylindrical shape and a horizontal cylindrical shape. it can. The stirring tank may be provided with a baffle plate or may not be provided with a baffle plate.

  In the case of using a stirring vessel, a stirring blade having an arbitrary shape can be selected, for example, a propeller blade, a flat paddle blade, a pitched paddle blade, a flat turbine blade, a pitched turbine blade, a ribbon blade, an anchor blade, a full zone blade, etc. Can be mentioned. One stirring blade may be provided, or a plurality of stirring blades may be provided.

  In order to mix raw water and (meth) acrylonitrile in the pipe, raw water and (meth) acrylonitrile can be mixed directly by connecting the raw water supply pipe and the (meth) acrylonitrile supply pipe. A method of positively mixing by installing a line mixer such as a static mixer is included.

  When mixing raw material water and (meth) acrylonitrile and supplying it to the reaction vessel, (meth) acrylonitrile may be completely dissolved in water after mixing with water, but not necessarily completely dissolved in water. It is not necessary to be mixed, and it may be mixed at an arbitrary ratio. The ratio of water: (meth) acrylonitrile is preferably 100: 1 to 1: 100, more preferably 50: 1 to 1:50, and even more preferably 10: 1 to 1:10 by volume.

  A known method can be used as the method for supplying the mixture of raw water and (meth) acrylonitrile when the raw water and (meth) acrylonitrile are mixed and then supplied to the reaction vessel. The method illustrated by the supply method of raw material water in the case of supplying water independently to a reaction tank can be used.

  When the raw water and (meth) acrylonitrile are mixed and then supplied to the reaction tank, the supply pipe for supplying the raw water and the (meth) acrylonitrile mixture to the reaction tank may be one per reaction tank. There may be more than one. There is no restriction | limiting in particular in the shape of the supply port of a supply pipe | tube, Any can be used suitably if it is a shape normally used.

  The (meth) acrylonitrile supplied to the reaction vessel may be supplied to the reaction vessel after being mixed with the raw water, or may be supplied alone to the reaction vessel. When supplying (meth) acrylonitrile alone to the reaction tank, the position of the supply port to the reaction liquid in the reaction tank of the (meth) acrylonitrile supply pipe is not particularly limited. It may be installed in the reaction solution.

  The method for supplying (meth) acrylonitrile in the case of supplying (meth) acrylonitrile alone to the reaction vessel is not particularly limited, and a known method can be used. Specifically, the above raw water is reacted. The method illustrated by the method of supplying to a tank can be used.

  The number of (meth) acrylonitrile supply pipes for supplying (meth) acrylonitrile to the reaction tank may be one per reaction tank or a plurality of (meth) acrylonitrile supply pipes. One (meth) acrylonitrile supply pipe may be provided for each supply pipe, or a plurality of supply ports may be provided.

  There is no restriction | limiting in particular in the shape of the supply port of a (meth) acrylonitrile supply pipe, Any can be used suitably if it is a shape normally used.

<Supply of pH regulator>
The pH adjusting agent supplied to the reaction vessel may be supplied to the reaction vessel alone, or after being mixed with the aqueous medium and / or the mixture containing the aqueous medium supplied to the reaction vessel, Also good. When supplying the pH regulator alone to the reaction tank, the position of the supply port to the reaction liquid in the reaction tank of the pH regulator supply pipe is not particularly limited. You may install in a reaction liquid.

The supply method of the pH adjuster when supplying the pH adjuster alone to the reaction vessel is not particularly limited, and a known method can be used. Specifically, the above raw water is supplied to the reaction vessel. The method exemplified in the supplying method can be used.
The number of pH adjusting agent supply pipes for supplying the pH adjusting agent to the reaction vessel may be one per reaction vessel, or a plurality of supply tubes may be provided. The supply port of the supply pipe for the pH adjusting agent may be one per supply pipe, or a plurality of supply ports may be provided.

The shape of the supply port of the pH adjusting agent supply pipe is not particularly limited, and any shape that is usually used can be suitably used.
The aqueous medium in which the pH adjusting agent is mixed when the pH adjusting agent and the aqueous medium and / or the mixture containing the aqueous medium are mixed and then supplied to the reaction vessel is preferably raw water. A mixture containing an aqueous medium in which a pH regulator is mixed is, for example, a reaction containing a mixture of raw water and (meth) acrylonitrile, a bacterial cell catalyst, an unreacted raw material, a pH regulator, and produced (meth) acrylamide. Liquid.

  A known method can be used as a method of mixing the pH adjuster and the raw water when the pH adjuster is supplied to the reaction tank after being mixed with the raw water. The method illustrated by the method of mixing water and (meth) acrylonitrile can be used.

  A known method can be used as a method for supplying the mixture of the pH regulator and the raw water when the pH regulator is mixed with the raw water and then supplied to the reaction tank. The method illustrated by the supply method of raw material water in the case of supplying to a reaction tank independently can be used.

  The pH regulator and the aqueous medium and / or the mixture containing the aqueous medium supplied to the reaction tank may be mixed at an arbitrary ratio, and preferably, the pH regulator: the aqueous medium and / or the mixture containing the aqueous medium. The ratio by volume is 1: 1 to 1: 100,000,000, more preferably 1:10 to 1: 10,000,000.

  A known method is used as a method of mixing the mixture of the pH regulator, the raw water and (meth) acrylonitrile when the pH regulator is mixed with the raw water and (meth) acrylonitrile and then supplied to the reaction vessel. Specifically, the method exemplified in the method of mixing the raw material water and (meth) acrylonitrile can be used.

  For example, the following method can be used as a method of mixing with a reaction liquid containing a pH regulator and a bacterial cell catalyst, an unreacted raw material, a pH regulator, and the produced (meth) acrylamide. An external circulation line equipped with a pump for returning a part of the reaction mixture to the reaction tank is installed in the reaction tank, and the reaction is performed as a mixture containing an aqueous medium by coupling the external circulation line and the pH regulator supply pipe. Examples include a method in which a part of the reaction mixture taken out from the tank is used and a part of the reaction mixture and the pH adjuster are directly mixed in an external circulation line. A part of the reaction mixture directly mixed in the external circulation line and the pH adjusting agent are supplied to the reaction tank as they are using the external circulation line.

<Supply of bacterial cell catalyst>
The supply of the bacterial cell catalyst is not particularly limited, and a known method can be used. As a method for supplying the bacterial cell catalyst to the reaction tank, a device having a liquid transport function can be used. For example, a turbo pump such as a centrifugal pump, a diagonal flow pump or an axial flow pump, a reciprocating pump or a rotary pump Pumps such as positive displacement pumps and conveyors such as screw conveyors can be used. As a method of supplying the bacterial cell catalyst, it can be supplied without using the device having the liquid transport function. When a device having a liquid transport function is not used, for example, a cell storage tank for storing cell catalysts is installed at the top of the reaction tank, the cell storage tank and the reaction tank are connected by a cell catalyst supply pipe, There is a method of supplying by dropping using. Or the method of supplying using the pressure difference of the microbial cell storage tank and reaction tank which arises by pressurizing a microbial cell storage tank or depressurizing a reaction tank is mentioned.

  The amount of the bacterial cell catalyst used varies depending on the reaction conditions, the type of catalyst and its form, but is usually 10 to 50,000 ppm by weight, preferably 10 to 50,000 ppm by weight, preferably in terms of the dry cell weight of the cells. 50 to 30,000 ppm by weight.

  The reaction time (retention time of the reaction solution) is usually 0.5 to 50 hours, preferably 2 to 25 hours. When a multistage reaction vessel is used, the reaction time refers to the total reaction time (retention time of the reaction liquid) in all reactors.

In the method for producing (meth) acrylamide of the present invention, the obtained (meth) acrylamide is recovered and purified by, for example, concentration operation (eg, evaporation concentration), activated carbon treatment, ion exchange treatment, filtration treatment, and crystallization operation. It can be carried out.
As described above, (meth) acrylamide can be obtained from (meth) acrylonitrile which is a reaction raw material.

[(Meth) acrylamide polymer]
The (meth) acrylamide polymer of the present invention is obtained by homopolymerizing (meth) acrylamide obtained as described above or copolymerizing with at least one unsaturated monomer copolymerizable with an amide compound. Can be manufactured.

<Unsaturated monomer>
Examples of unsaturated monomers copolymerizable with (meth) acrylamide include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and salts thereof;
Sulfonic acids such as vinyl sulfonic acid, styrene sulfonic acid, acrylamidomethylpropane sulfonic acid and their salts;
Alkylaminoalkyl esters of (meth) acrylic acid such as N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, or quaternary ammonium derivatives thereof;
N, N-dialkylaminoalkyl (meth) acrylamides such as N, N-dimethylaminopropylmethacrylamide, N, N-dimethylaminopropylacrylamide, or quaternary ammonium derivatives thereof;
Hydrophilic acrylamides such as diacetone acrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N-ethylmethacrylamide, N-ethylacrylamide, N, N-diethylacrylamide, N-propylacrylamide;
N-acryloylpyrrolidine, N-acryloylpiperidine, N-acryloylmorpholine;
Hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate;
Methoxypolyethylene glycol (meth) acrylate, N-vinyl-2-pyrrolidone;
Acrylamide;
Methacrylamide;
N, N-di-n-propylacrylamide, Nn-butylacrylamide, Nn-hexylacrylamide, Nn-hexylmethacrylamide, Nn-octylacrylamide, Nn-octylmethacrylamide, N- N-alkyl (meth) acrylamide derivatives such as tert-octylacrylamide, Nn-dodecylacrylamide, Nn-dodecylmethacrylamide;
N, N-diglycidylacrylamide, N, N-diglycidylmethacrylamide, N- (4-glycidoxybutyl) acrylamide, N- (4-glycidoxybutyl) methacrylamide, N- (5-glycidoxy N- (ω-glycidoxyalkyl) (meth) acrylamide derivatives such as pentyl) acrylamide, N- (6-glycidoxyhexyl) acrylamide;
(Meth) acrylate derivatives such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate;
Examples include olefins such as acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, ethylene, propylene, and butene, styrene, α-methylstyrene, butadiene, and isoprene.
These monomers may be used alone or in combination of two or more.

<Polymerization initiator>
As the polymerization initiator, for example, a radical polymerization initiator can be used.
Examples of radical polymerization initiators include peroxides such as potassium persulfate, ammonium persulfate, hydrogen peroxide, and benzoyl peroxide; azobisisobutyronitrile, 2,2′-azobis (4-amidinopropane) dihydrochloride, Azo free radical initiators such as 4,4'-azobis (sodium 4-cyanovalerate);
Examples thereof include so-called redox catalysts in which the peroxide is used in combination with a reducing agent such as sodium bisulfite, triethanolamine, and ferrous ammonium sulfate.

  The above polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator is usually in the range of 0.001 to 5% by weight based on the total weight of the monomers.

In the case of a single polymerization initiator, the polymerization temperature is usually in the range of 0 to 120 ° C, more preferably in the range of 5 to 90 ° C. Further, the polymerization temperature does not always need to be maintained at a constant temperature, and may be appropriately changed as the polymerization proceeds. Usually, however, the polymerization temperature tends to increase as the polymerization proceeds. Therefore, it may be cooled as necessary.
The molecular weight of the (meth) acrylamide polymer of the present invention is not particularly limited, but is usually in the range of 100,000 to 50 million, and preferably in the range of 500,000 to 30 million.

  The (meth) acrylamide polymer thus obtained is a polymer that has both water-solubility and high molecular weight, and is excellent in hue, and has a flocculant, paper additive, and oil recovery. It can be suitably used as an agent.

[Production method of (meth) acrylamide polymer]
As a manufacturing method of the (meth) acrylamide type polymer of this invention, aqueous solution polymerization, emulsion polymerization, etc. can be used, for example.

Among these, in the case of aqueous solution polymerization, the total concentration of (meth) acrylamide and the unsaturated monomer added as needed is usually 5 to 90% by weight. The atmosphere during polymerization is not particularly limited, From the viewpoint of proceeding the polymerization quickly, it is preferable to perform the polymerization in an inert gas atmosphere such as nitrogen gas.
The polymerization time is not particularly limited, but is usually in the range of 1 to 20 hours.

The pH of the aqueous solution at the time of polymerization is not particularly limited, but polymerization may be carried out by adjusting the pH if necessary. In this case, usable pH adjusters include alkalis such as sodium hydroxide, potassium hydroxide and ammonia;
Mineral acids such as phosphoric acid, sulfuric acid, hydrochloric acid;
Examples include organic acids such as formic acid and acetic acid.

  Next, examples of the present invention will be specifically described, but the present invention is not limited to these examples.

[Example 1]
[Preparation of microbial cells containing nitrile hydratase]
In accordance with the method described in Example 1 of JP-A-2001-340091, no. Three clone cells were obtained and similarly cultured by the method of Example 1 to obtain wet cells containing nitrile hydratase.

[Purification of Acrylonitrile]
As a distillation apparatus, a glass 5 L round bottom flask equipped with a Dimroth type cooling coagulator and a packed tower corresponding to 8 stages was prepared.

  3 kg of acrylonitrile (manufactured by INEOS) having a crotononitrile concentration of 180 ppm was charged into the apparatus in a round bottom flask and subjected to a distillation operation. An oil bath was used for heating, and the fraction until the distillation temperature reached 77 ° C. was defined as the first fraction. 2 kg of a fraction having a distillation temperature of 77 to 78 ° C. was obtained as a main fraction. When the main sample was analyzed under the following conditions, the crotononitrile concentration was below the detection limit (1 ppm or less). Hereinafter, the acrylonitrile after the distillation treatment is referred to as acrylonitrile a.

Here, the analysis conditions were as follows.
・ Acrylonitrile analysis conditions:
Gas chromatograph: GC-14B system (manufactured by Shimadzu Corporation)
(FID detection, column temperature 100 ° C.)
Separation column: Chromosorb W, AW-DMCS
I. D. 3.2φx4.1m (manufactured by Shinwa Kako Co., Ltd.)
Carrier gas: N2

[Production of acrylamide]
In order to obtain a final product having an acrylamide concentration in the aqueous solution of 50% by weight, the reaction was performed under the following conditions.

    A 1 L glass flask equipped with a stirrer was prepared as the first reactor, and a Teflon (registered trademark) tube 20 m having an inner diameter of 5 mm was prepared as the second reactor. The raw water supply pipe, the pH regulator supply pipe, the acrylonitrile supply pipe, and the cell catalyst supply pipe are each directly connected to the first reactor.

  The first reactor was charged with 400 g of water in advance. The wet cells obtained by the above culture method were suspended in pure water. This suspension was continuously fed at a rate of 10 g / h while stirring in the first reactor. Acrylonitrile a was continuously supplied at a rate of 32 g / h, and pure water was continuously supplied at a rate of 38 g / h. The temperature of the reaction solution during the reaction was controlled by immersing both the first reactor and the second reactor in a water bath having a temperature of 10 to 20 ° C. A 0.1 M NaOH aqueous solution was used as a pH adjuster, the supply amount was adjusted so that the reaction pH was 7.5 to 8.5, and the solution was continuously supplied to the first reactor.

  In order to keep the liquid level of the first reactor constant, the reaction solution is continuously withdrawn from the first reactor at a rate of 80 g / h and continuously supplied to the second reactor. The reaction was allowed to proceed further within.

  Analysis was performed under the following HPLC conditions 50 hours after the start of the reaction. The conversion to acrylamide at the outlet of the first reactor was 95%, and the acrylonitrile concentration at the outlet of the second reactor was below the detection limit (10 ppm). The following).

Here, the analysis conditions were as follows.
・ Acrylamide analysis conditions:
High-performance liquid chromatograph: LC-10A system (manufactured by Shimadzu Corporation)
(UV detector wavelength 250 nm, column temperature 40 ° C.)
Separation column: SCR-101H (manufactured by Shimadzu Corporation)
Eluent: 0.05% (volume basis) -phosphoric acid aqueous solution / acrylonitrile analysis conditions:
High-performance liquid chromatograph: LC-10A system (manufactured by Shimadzu Corporation)
(UV detector wavelength 200 nm, column temperature 40 ° C.)
Separation column: Wakosil-II 5C18HG (manufactured by Wako Pure Chemical Industries)
Eluent: 7% (volume basis) -acetonitrile, 0.1 mM-
Acetic acid, 0.2 mM sodium acetate at each concentration
Aqueous solution

[Production of acrylamide polymer]
The reaction mixture obtained by the above method was treated with activated carbon under acidic conditions (pH = 5) to remove wet cells, and further neutralized with a 0.1 M NaOH aqueous solution to concentrate 50% by weight of acrylamide. An aqueous solution was obtained.

  Water was added to the obtained aqueous acrylamide solution to obtain an aqueous acrylamide solution having a concentration of 20% by weight. 500 g of this 20 wt% acrylamide aqueous solution was placed in a 1 L polyethylene container, and while maintaining the temperature at 18 ° C., dissolved oxygen in the liquid was removed through nitrogen, and immediately placed in a heat insulating block made of polystyrene foam.

Then 200 × 10 ⁻⁶ mpm (molar ratio to acrylamide) 4,4′-azobis (sodium 4-cyanovalerate), 200 × 10 ⁻⁶ mpm dimethylaminopropionitrile, and 80 × 10 ⁻⁶ mpm Of ammonium persulfate were each dissolved in a small amount of water and quickly poured into a 1 L polyethylene container in this order. Nitrogen gas was previously passed through these reagents, and before and after injection, a small amount of nitrogen gas was also passed through the polyethylene container to prevent oxygen gas from being mixed.

  When the reagent was injected, after the induction period of several minutes, the temperature inside the polyethylene container was observed to rise, so the supply of nitrogen gas was stopped. When the polyethylene container was held in the heat insulation block for about 100 minutes, the temperature inside the polyethylene container reached about 70 ° C. Therefore, the polyethylene container was taken out from the heat insulation block and immersed in 97 ° C. water for 2 hours to further proceed the polymerization reaction. Thereafter, it was immersed in cold water and cooled to stop the polymerization reaction.

  The water-containing gel of acrylamide polymer thus obtained was taken out from the polyethylene container, divided into small chunks and ground with a meat grinder. The ground hydrogel containing acrylamide polymer was dried with hot air at 100 ° C. for 2 hours and then pulverized with a high-speed rotary blade pulverizer to obtain a dry powdery acrylamide polymer. The obtained dry powdery acrylamide polymer was passed through a sieve, and a 32-42 mesh sample was collected and used as a polymer sample for subsequent tests.

[Example 2]
Crotononitrile (manufactured by Tokyo Chemical Industry Co., Ltd., purity 98%) was added to acrylonitrile a described in Example 1 to adjust the crotononitrile concentration in acrylonitrile to 40 ppm. Hereinafter, the acrylonitrile is referred to as acrylonitrile b.
In the production of acrylamide of Example 1, acrylamide was produced in the same manner as in Example 1 except that acrylonitrile b was used instead of acrylonitrile a. When HPLC analysis was performed 50 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 92%, and the acrylonitrile concentration at the outlet of the second reactor was 15 ppm.

  Since acrylonitrile was detected at the outlet of the second reactor, the supply rate of the wet cell suspension was changed from 10 g / h to 11 g / h in order to complete the reaction. Acrylamide was produced. When HPLC analysis was performed 50 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 95%, and the acrylonitrile concentration at the outlet of the second reactor was below the detection limit (10 ppm or less). Completed.

  In the production of the acrylamide polymer of Example 1, instead of using the acrylamide aqueous solution obtained from acrylonitrile a, the acrylamide polymer was prepared in the same manner as in Example 1 except that the acrylamide aqueous solution obtained from acrylonitrile b was used. Manufactured. The obtained water-containing gel of acrylamide polymer was treated in the same manner as in Example 1 to obtain a polymer sample for use in the subsequent tests.

[Example 3]
Crotononitrile (Tokyo Chemical Industry Co., Ltd., purity 98%) was added to acrylonitrile a described in Example 1 to adjust the crotononitrile concentration in acrylonitrile to 70 ppm. Hereinafter, the acrylonitrile is referred to as acrylonitrile c.

  In the production of acrylamide of Example 1, acrylamide was produced in the same manner as in Example 1 except that acrylonitrile c was used instead of acrylonitrile a. When HPLC analysis was performed 50 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 88%, and the acrylonitrile concentration at the outlet of the second reactor was 40 ppm.

  Since acrylonitrile was detected at the outlet of the second reactor, the supply rate of the wet cell suspension was changed from 10 g / h to 13 g / h in order to complete the reaction. Acrylamide was produced. When HPLC analysis was performed 50 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 95%, and the acrylonitrile concentration at the outlet of the second reactor was below the detection limit (10 ppm or less). Completed.

  In the production of the acrylamide polymer of Example 1, instead of using the acrylamide aqueous solution obtained from acrylonitrile a, the acrylamide polymer was prepared in the same manner as in Example 1 except that the acrylamide aqueous solution obtained from acrylonitrile c was used. Manufactured. The obtained water-containing gel of acrylamide polymer was treated in the same manner as in Example 1 to obtain a polymer sample for use in the subsequent tests.

[Comparative example]
In the production of acrylamide of Example 1, acrylamide was produced in the same manner as in Example 1 except that unpurified acrylonitrile was used instead of acrylonitrile a. When HPLC analysis was performed 50 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 76%, and the acrylonitrile concentration at the outlet of the second reactor was 900 ppm.

Since acrylonitrile was detected at the outlet of the second reactor, the supply rate of the wet cell suspension was changed from 10 g / h to 21 g / h in order to complete the reaction. Acrylamide was produced. When HPLC analysis was performed 50 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 95%, and the acrylonitrile concentration at the outlet of the second reactor was below the detection limit (10 ppm or less). Completed.
In the production of the acrylamide polymer of Example 1, instead of using the acrylamide aqueous solution obtained from acrylonitrile a, the acrylamide polymer was used in the same manner as in Example 1 except that the acrylamide aqueous solution obtained from unpurified acrylonitrile was used. Coalescence was produced. The obtained water-containing gel of acrylamide polymer was treated in the same manner as in Example 1 to obtain a polymer sample for use in the subsequent tests.

<Testing method for acrylamide polymer>
Evaluation of water solubility, measurement of standard viscosity, and evaluation of color tone of the polymer samples obtained in Examples 1, 2, 3 and Comparative Examples were performed by the following methods.

  Water solubility: In water solubility, 600 ml of water is put into a 1 L beaker, and 0.66 g (pure content 0.6 g) of polymer sample is added while stirring at 25 ° C. using a stirring blade having a predetermined shape. Stirring was performed for a period of time, and the resulting solution was filtered through a 150-mesh wire mesh, and water solubility was judged from the amount of insoluble matter and filterability. That is, ◎ is completely dissolved, ◯ is close to completely dissolved, there is an insoluble matter, △ is what can be filtered, △, the passage of the filtrate is slow, the insoluble matter is effectively filtered The thing which cannot be made was set as x.

Standard viscosity: The filtrate obtained by the above water solubility test is a polymer aqueous solution having a concentration of 0.1% by weight. To this, sodium chloride corresponding to a concentration of 1M is added, and a BL type viscometer is used with a BL adapter at 25 ° C. The viscosity was measured at a rotor rotational speed of 60 rpm (standard viscosity). The standard viscosity obtained by such a method is conventionally used as a value correlated with the molecular weight.
Color tone: Regarding the color tone of the polymer, the polymer powder was visually evaluated.
The evaluation results are shown in Table 1.

Claims (4)

A method for producing (meth) acrylamide, characterized by hydrating a (meth) acrylonitrile having a crotononitrile concentration of 100 ppm or less with a nitrile hydratase-containing microbial cell and / or a treated product thereof. The method according to claim 1, wherein the nitrile hydratase is a nitrile hydratase derived from Pseudonocardia or Rhodococcus. A (meth) acrylamide polymer obtained by homopolymerizing the (meth) acrylamide according to claim 1 or copolymerizing with at least one unsaturated monomer copolymerizable with an amide compound. A method for producing a (meth) acrylamide polymer, characterized in that the (meth) acrylamide according to claim 1 is homopolymerized or copolymerized with at least one unsaturated monomer copolymerizable with an amide compound.