U.S. patent application number 12/089511 was filed with the patent office on 2009-07-02 for method for producing amide compound.
This patent application is currently assigned to MITSUI CHEMICALS, INC.. Invention is credited to Takeya Abe, Toshikazu Aikawa, Teruo Arii, Takeshi Fukuda, Souichi Hazama, Kiyoshi Ito, Masanori Muramoto, Hiroko Shibamoto.
Application Number | 20090171051 12/089511 |
Document ID | / |
Family ID | 37942709 |
Filed Date | 2009-07-02 |
United States Patent
Application |
20090171051 |
Kind Code |
A1 |
Shibamoto; Hiroko ; et
al. |
July 2, 2009 |
Method For Producing Amide Compound
Abstract
[Problems] The present invention provides a method for
efficiently producing a corresponding amide compound from a nitrile
compound by a reaction using a nitrile hydratase and a method for
producing an amide-based polymer excellent in quality from the
amide compound. In addition, the present invention provides a
method for more efficiently producing an acrylamide with higher
quality by a microbial catalyst containing a nitrile hydratase and
the like and a method for producing an acrylamide-based polymer,
which is excellent in hue, has a good balance between the water
solubility and the high molecular weight and is also excellent in
quality, by using the acrylamide. [Means for Solving the Problems]
The method for producing an amide compound of the present invention
is characterized in that in a method for producing an amide
compound from a nitrile compound in an aqueous medium in the
presence of a catalyst having a nitrile hydratase activity, the
concentration of benzene in the aqueous medium is 4.0 ppm or less.
In addition, the method for producing an amide-based polymer of the
present invention is characterized by homopolymerizing the amide
compound or by copolymerizing the amide compound and at least
unsaturated monomer copolymerizable with the amide compound.
Further, the method for producing acrylamide of the present
invention is characterized by hydrating acrylonitrile having a
concentration of acrolein of 1 ppm or less by a microbial cell
containing a nitrile hydratase or a processed product of the
microbial cell in an aqueous medium. Furthermore, the method for
producing an acrylamide-based polymer of the present invention is
characterized by homopolymerizing the acrylamide or by
copolymerizing the acrylamide and at least one unsaturated monomer
copolymerizable with the acrylamide.
Inventors: |
Shibamoto; Hiroko; ( Chiba,
JP) ; Aikawa; Toshikazu; (Chiba, JP) ; Arii;
Teruo; (Chiba, JP) ; Muramoto; Masanori;
(Osaka, JP) ; Fukuda; Takeshi; (Osaka, JP)
; Ito; Kiyoshi; (Tokyo, JP) ; Abe; Takeya;
(Osaka, JP) ; Hazama; Souichi; (Osaka,
JP) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
MITSUI CHEMICALS, INC.
Minatoku, Tokyo
JP
|
Family ID: |
37942709 |
Appl. No.: |
12/089511 |
Filed: |
October 6, 2006 |
PCT Filed: |
October 6, 2006 |
PCT NO: |
PCT/JP2006/320087 |
371 Date: |
April 7, 2008 |
Current U.S.
Class: |
526/303.1 ;
435/129 |
Current CPC
Class: |
C08F 220/56 20130101;
C12P 13/02 20130101; C12P 13/00 20130101; C07C 231/06 20130101;
C07C 231/06 20130101; C07C 233/09 20130101 |
Class at
Publication: |
526/303.1 ;
435/129 |
International
Class: |
C08F 22/38 20060101
C08F022/38; C12P 13/02 20060101 C12P013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2005 |
JP |
2005-295561 |
Dec 27, 2005 |
JP |
2005-375024 |
Claims
1. A method for producing an amide compound from a nitrile compound
in an aqueous medium in the presence of a catalyst having a nitrile
hydratase activity, wherein the concentration of benzene in the
aqueous medium is 4.0 ppm or less.
2. The method for producing an amide compound according to claim 1,
wherein the nitrile hydratase is a nitrile hydratase derived from
Pseudonocardia or derived from Rhodococcus.
3. The method for producing an amide compound according to claim 1,
wherein the nitrile compound is acrylonitrile or
methacrylonitrile.
4. A method for producing an amide-based polymer, comprising
homopolymerizing the amide compound according to claim 1 or
copolymerizing the amide compound and at least one unsaturated
monomer copolymerizable with the amide compound.
5. The method for producing an amide-based polymer according to
claim 4, wherein the amide compound is acrylamide or
methacrylamide.
6. A method for producing an acrylamide, comprising hydrating an
acrylonitrile having an acrolein concentration of 1 ppm or less by
a microbial cell containing a nitrile hydratase or a processed
product of the microbial cell in an aqueous medium.
7. A method for producing an acrylamide-based polymer, comprising
homopolymerizing the acrylamide according to claim 6 or
copolymerizing the acrylamide and at least one unsaturated monomer
copolymerizable with the acrylamide.
8. The method for producing an amide compound according to claim 2,
wherein the nitrile compound is acrylonitrile or methacrylonitrile.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for producing an
amide compound.
[0002] The present invention (the first invention) relates more
particularly to methods for producing an amide compound and an
amide-based polymer and further more particularly to a method for
efficiently producing a corresponding amide compound from a nitrile
compound in an aqueous medium by the use of a catalyst having a
nitrile hydratase activity, and a method for producing an
amide-based polymer of high quality from the amide compound. In
addition, the present invention (the second invention) relates more
particularly to methods for producing an acrylamide and an
acrylamide-based polymer and further more particularly to a method
for producing an acrylamide of high quality by hydrating an
acrylonitrile using a microbial cell containing a nitrile hydratase
and the like; and to a method for producing an acrylamide-based
polymer of high quality from the acrylamide.
BACKGROUND ART
[0003] As mentioned below, various production methods have been
disclosed for industrially useful amide compounds.
[0004] Recently, there have been discovered nitrile hydratases
having a nitrile hydration activity capable of converting a nitrile
group into an amide group through hydration and there has been
already disclosed a method for producing a corresponding amide
compound from a nitrile compound by the use of the enzyme, a
microbial cell containing the enzyme, or the like. The production
method is known to have benefits such as a high conversion and a
high selectivity from the nitrile compound to the corresponding
amide compound, compared to the conventional scientific
methods.
[0005] In industrially producing an amide compound by using these
nitrile hydratases, it is important to maximize the amide compound
productivity of the nitrile hydratases as catalysts (the number of
molecules of the amide compound produced per one molecule of the
nitrile hydratase). For this reason, numerous proposals have been
made for the purposes of maintaining and increasing the enzyme
activity, preventing the activity deterioration, recovering the
deteriorated enzyme activity and the like. For example, it is well
known that the enzyme activity is maintained and increased by
contacting a microbial cell containing a nitrile hydratase or a
processed product of the microbial cell with an oxidant in the
conditions where the cells are not allowed to grow (see Patent
Document 1). Further, it is well known that the activity
deterioration of a nitrile hydratase is prevented by using a
nitrile compound in which the concentration of the contained
hydrocyanic acid is reduced (see Patent Document 2). In addition,
there are known a method in which the reaction is carried out by
using a microbial cell crosslinked with glutaraldehyde (see Patent
Document 3), a method in which the reaction is carried out in the
presence of a higher unsaturated fatty acid or its salt (see Patent
Document 4), a method in which the reaction is carried out by using
a microbial cell processed with an organic solvent or a processed
product thereof (see Patent Document 5), and the like. The above is
the background art of the first invention.
[0006] Further, as mentioned above, one of the main methods for
producing acrylamide is a method of hydrating acrylonitrile. For
example, there is known a method of hydrating acrylonitrile with a
metallic copper catalyst such as Raney copper or the like or a
method of hydrating acrylonitrile by using a microbial cell
containing a nitrile hydratase, a processed product of the
microbial cell, or the like as a catalyst.
[0007] Among these, as an industrial production method, the method
for producing acrylamide using the microbial cell containing the
nitrile hydratase or the like as a catalyst, has attracted
attention because the method has a high conversion and a high
selectivity of acrylonitrile, compared to the conventional method
of hydration using the metallic copper catalyst and the like.
[0008] In order to efficiently produce acrylamides with higher
quality by using the microbial cell containing the nitrile
hydratase, and the like as a catalyst, impurities inhibiting the
catalytic action of the microbial cell and the like are required to
be removed as much as possible.
[0009] In addition, acrylamides obtained by such reactions are
mainly used as a raw material for an acrylamide-based polymer.
However, recently a further improvement of the quality is required
for the acrylamide-based polymer. For example, the applications of
an acrylamide-based polymer include a flocculant. Recently, the
acrylamide-based polymer used as a flocculent is expected to have a
higher molecular weight while maintaining the water solubility to
improve the performance. Further, the acrylamide-based polymer is
used as an additive for manufacturing paper, and the like, and, as
the additive for manufacturing paper, a polymer being more
excellent in hue is required in order to further improve the
quality of the resulting paper.
[0010] As a method for improving the quality of the acrylamide
obtained with use of cellular catalysts containing the nitrile
hydratase, and the like or the quality of the polyacrylamide, as
mentioned above, there are known a method in which the
concentration of hydrocyanic acid in a nitrile compound is reduced
by a chemical process and then the nitrile hydratase is allowed to
act on the nitrile compound to produce an amide compound (for
example, see Patent Document 2), and a method in which oxazole and
hydrocyanic acid contained in acrylonitrile as impurities are
reduced and then the acrylonitrile is converted into acrylamide,
followed by producing an acrylamide-based polymer from the
acrylamide (for example, see Patent Document 6). The above is the
background art of the second invention.
[0011] [Patent Document 1] Japanese Patent Application Laid-Open
Publication No. 2004-350573
[0012] [Patent Document 2] Japanese Patent Application Laid-Open
Publication No. 11-123098
[0013] [Patent Document 3] Japanese Patent Application Laid-Open
Publication No. H7-265091
[0014] [Patent Document 4] Japanese Patent Application Laid-Open
Publication No. H7-265090
[0015] [Patent Document 5] Japanese Patent Application Laid-Open
Publication No. H5-308980
[0016] [Patent Document 6] International Publication WO
2004/090148
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0017] However, the productivity of the amide compound using the
nitrile hydratase is decreased due to other factors that are not be
resolved by the conventional techniques described in the background
art of the first invention, and it has also been desired to resolve
the factors in order to efficiently produce the amide compound
using the nitrile hydratase.
[0018] Accordingly, an object of the first invention is to provide
a method for efficiently producing a corresponding amide compound
from a nitrile compound by a reaction using a nitrile hydratase. In
addition, another object of the first invention is to provide a
method for producing an amide-based polymer with high quality using
the amide compound produced by the above method.
[0019] Further, according to the methods described in the
background art of the second invention, sufficient effects may not
be always obtained from the viewpoints of eliminating a factor that
inhibits the catalytic action of a microbial cell containing a
nitrile hydratase and the like and efficiently performing hydration
of acrylonitrile. In addition, there is still room for improvement
from the viewpoint of improving the quality of the acrylamide and
acrylamide-based polymer.
[0020] Therefore, an object of the second invention is to provide a
method for more efficiently producing acrylamide with higher
quality using a cellular catalyst containing a nitrile hydratase
and the like and a method for producing an acrylamide-based
polymer, which is excellent in hue, has a good balance between the
water solubility and the high molecular weight and is also
excellent in quality, by using the acrylamide.
Means for Solving the Problems
[0021] The present inventors have earnestly studied on the
production method for an amide compound in order to solve the above
problems of the first invention. The present inventors have found
that, in a method for producing a corresponding amide compound from
a nitrile compound in an aqueous medium using a catalyst having a
nitrile hydratase activity, the amide compound may be efficiently
produced without reducing the reaction rate of the nitrile
hydratase when the concentration of benzene in the aqueous medium
is reduced to a specific value or lower. In general, benzene in the
aqueous medium is derived from the nitrile compound that is a raw
material. Even when it is derived from other sources, the amide
compound may be efficiently produced by reducing the concentration
of benzene to the same level as the above. In addition, an
amide-based polymer excellent in hue may be obtained by using the
amide compound produced by the above method, under the reaction
conditions in which the concentration of benzene is reduced as
described.
[0022] That is, the first invention is as follows.
[0023] [1] A method for producing an amide compound from a nitrile
compound in an aqueous medium in the presence of a catalyst having
a nitrile hydratase activity, wherein the concentration of benzene
in the aqueous medium is 4.0 ppm or less.
[0024] [2] The method for producing an amide compound described in
[1] in which the nitrile hydratase is a microbe producing a nitrile
hydratase derived from Pseudonocardia or Rhodococcus.
[0025] [3] The method for producing an amide compound described in
[1] or [2] in which a nitrile compound is acrylonitrile or
methacrylonitrile.
[0026] [4] A method for producing an amide-based polymer by
homopolymerizing the amide compound described in [1] or by
copolymerizing the amide compound and at least one unsaturated
monomer copolymerizable with the amide compound.
[0027] [5] The method for producing an amide-based polymer
described in [4] in which the amide compound is acrylamide or
methacrylamide.
[0028] In addition, the present inventors have studied the problems
of the second invention and found that the catalytic activity of a
nitrile hydratase may be maintained and an acrylamide with high
quality may be obtained by reducing the concentration of acrolein
contained in an acrylonitrile, and further found that an
acrylamide-based polymer which is excellent in hue and has a good
balance between the water solubility and the high molecular weight
may be obtained from the acrylamide, and thus accomplished the
second invention.
[0029] In other words, the method for producing acrylamide of the
second invention is characterized in that an acrylonitrile in which
the concentration of acrolein is 1 ppm or less is hydrated in an
aqueous medium with a microbial cell containing a nitrile hydratase
or a processed product of the microbial cell.
[0030] The concentration of hydrocyanic acid contained in the above
acrylonitrile is preferably 5 ppm or less.
[0031] Further, the concentration of oxazole contained in the
acrylonitrile is also preferably 10 ppm or less.
[0032] Furthermore, it is also preferable that the concentration of
hydrocyanic acid contained in the above acrylonitrile is 5 ppm or
less and the concentration of oxazole contained in the above
acrylonitrile is 10 ppm or less.
[0033] The method for producing an acrylamide-based polymer of the
second invention is characterized in that the above acrylamide is
homopolymerized or the above acrylamide is copolymerized with at
least one unsaturated monomer copolymerizable with the
acrylamide.
EFFECT OF THE INVENTION
[0034] According to the first invention, in the reaction using a
nitrile hydratase, a corresponding amide compound may be
efficiently produced from a nitrile compound by reducing the
concentration of benzene in an aqueous medium containing the
nitrile compound to the specific value or lower. In addition, an
amide-based polymer excellent in hue may be obtained by using the
amide compound produced by the above method, under the reaction
conditions in which the concentration of benzene is reduced as
described.
[0035] Further, according to the second invention, an acrylamide
with higher quality may be more efficiently produced by a microbial
catalyst containing a nitrile hydratase and the like. Furthermore,
according to the second invention, there may be obtained an
acrylamide-based polymer that is excellent in hue, has a good
balance between the water solubility and the high molecular weight,
and is also excellent in quality.
BEST MODE FOR CARRYING OUT THE INVENTION
1. The First Invention
[0036] Hereinafter, the first invention will be explained in
detail.
[0037] A catalyst having a nitrile hydratase activity used in the
first invention is a microbial cell producing a nitrile hydratase
or a processed product of the microbial cell. The term "nitrile
hydratase" here is a protein having an ability of hydrating a
nitrile compound. The microbes producing a nitrile hydratase
include microbes belonging to Nocardia, Corynebacterium, Bacillus,
thermophilic Bacillus, Pseudomonas, Micrococcus, Rhodococcus
represented by rhodochrous species, Acinetobacter, Xanthobacter,
Streptomyces, Rhizobium, Klebsiella, Enterobacter, Erwinia,
Aeromonas, Citrobacter, Achromobacter, Agrobacterium,
Pseudonocardia represented by thermophila species, Bacteridium,
Brevibacterium and the like. Preferable are microbes belonging to
Pseudonocardia and Rhodococcus and especially preferable are
Pseudonocardia thermophila JCM3095 and Rhodococcus rhodochrous
J-1.
[0038] Further, the microbes producing the nitrile hydratase in the
first invention also include a transformant obtained by expressing
a nitrile hydratase gene cloned from the above-mentioned microbe in
an arbitrary host. The arbitrary hosts referred to herein are not
particularly limited, and include Escherichia coli as a
representative example as in the case of Examples described later,
Bacillus such as Bacillus subtilis and the like and other macrobial
strains such as yeasts, Actinomyces and the like. Examples thereof
include MT-10822 (the strain deposited at National Institute of
Bioscience and Human Technology, Agency of Industrial Science and
Technology, Ministry of International Trade and Industry, 1-3,
Higashi 1-chome, Tsukuba-shi, Ibaraki-ken, Japan on Feb. 7, 1996,
under an accession number FERM BP-5785, under the terms of the
Budapest Treaty on the International Recognition of the Deposit of
Microorganisms for the Purposes of Patent Procedure). The microbes
producing the nitrile hydratase in the first invention also include
transformants expressing a mutant nitrile hydratase that are
obtained by replacing, deleting, eliminating or inserting one or
two or more of constituent amino acids of the enzyme with other
amino acids by using recombinant DNA technology and thereby have
been further improved in amide compound resistance, nitrile
compound resistance and temperature resistance.
[0039] In using the microbe producing the nitrile hydratase in a
production method of the first invention, the microbial cell or the
processed product of the microbial cell is generally used. The
microbial cell may be prepared by using a general method well known
in the fields of molecular biology, bioengineering and genetic
engineering. For example, there may be mentioned a method in which
the microbe is planted in typical liquid culture mediums such as an
LB medium, an M9 medium and the like and then is grown at an
appropriate culture temperature (which is generally from 20.degree.
C. to 50.degree. C., and may be 50.degree. C. or higher in the case
of a thermophilic bacterium), and the microbe is separated and
recovered from the culture liquid using a centrifugal
separation.
[0040] In addition, the processed products of the microbial cells
are not particularly limited in the shape and include an extract
and a ground product of the above microbial cell; a post-separated
product obtained by separating and purifying a nitrile hydratase
active fraction of the extract and the ground product; and an
immobilized product obtained by immobilizing the microbial cell, or
the extract, the ground product or the post-separated product of
the microbial cell using an appropriate carrier. These are usable
as the processed product of the microbial cell in the first
invention as long as they have the nitrile hydratase activity.
[0041] The microbial cell producing the nitrile hydratase or the
processed product of the microbial cell may be used for the
reaction immediately after production, or may be stored after
production and used as needed.
[0042] The microbial cell producing the nitrile hydratase or the
processed product of the microbial cell in the first invention may
be used in either a batch reaction or a continuous reaction. In
addition, the reactor type may be selected from a suspended bed, a
fixed bed, a fluidized bed or the like, depending on the form of
the microbial cell or the processed product of the microbial cell.
The concentration of catalyst in the reaction solution is not
particularly limited as long as it does not disturb the mixing of
an aqueous medium and the nitrile compound.
[0043] The aqueous medium in the first invention refers to water or
an aqueous solution (the whole reaction solution) in which there
are dissolved a buffer agent such as a phosphate or the like, an
inorganic salt such as a sulfate, carbonate or the like, a
hydroxide of alkali metal, the amide compound, the nitrile
compound, the catalyst having a nitrile hydratase activity or the
like at a suitable concentration. In the first invention, even if
the reaction is carried out in a homogeneous system in which the
concentration of the nitrile compound in the aqueous solution is
less than a saturated concentration or in a two-phase system
consisting of a nitrile phase and a water phase in which system the
concentration of the nitrile compound is at a saturated
concentration or more, the whole solution is defined as the aqueous
medium. Further, in the present specification, the aqueous medium
in the first invention is also referred to as "the aqueous medium
(I)". In the case of the two-phase system where two phases are
separated under static conditions, it is important to sufficiently
mix the water phase and the nitrile phase by using a suitable
mixing apparatus such as a rotary blade, a line mixer or the
like.
[0044] In the first invention, the concentration of the nitrile
compound in the aqueous medium (I) during the reaction is not
particularly limited as long as the reaction rate is not reduced by
the concentration of benzene in the aqueous medium (I) or as long
as the nitrile hydratase is not deactivated by the nitrile
compound. The percent by weight of the nitrile compound is
preferably 50% by weight or less.
[0045] The nitrile compound used in the first invention is not
particularly limited as long as it is a compound that may be
converted to an amide compound by the catalyst having the nitrile
hydratase activity in the aqueous medium (I). The representative
examples preferably include nitrile compounds having 2 to 4 carbon
atoms such as acetonitrile, propionitrile, acrylonitrile,
methacrylonitrile, n-butyronitrile, isobutyronitrile,
crotononitrile, .alpha.-hydroxyisobutyronitrile and the like. More
preferably acrylonitrile and methacrylonitrile are used.
[0046] Although commercially available nitrile compounds are
purified during production, small amounts of impurities are
unavoidable. One of the impurities is benzene. For example, benzene
is contained in a commercially available acrylonitrile product
because the acrylonitrile product is industrially produced by
ammoxidation of propylene that contains a small amount of
benzene.
[0047] The concentration of benzene contained in the aqueous medium
(I) may be such that the reduction of the reaction rate is
prevented and typically is 4.0 ppm or less and preferably is 2.2
ppm or less. Here, the words the reduction of the reaction rate is
prevented mean that the reaction rate is 80% of more relative to
the reaction rate (100%) achieved when the benzene concentration in
the aqueous medium (I) is not more than 2.2 ppm. In addition, the
phrase "the concentration of benzene contained in the aqueous
medium (I) is 4.0 ppm or less" means that the amount of benzene
contained in 1 kg of the aqueous medium (I) is 4 mg or less. Any
process may be used for the process of removing benzene from the
nitrile compound or for the process of removing benzene from the
aqueous medium (I). For example, there may be mentioned
distillation, an adsorption treatment with activated carbon, an
adsorption treatment with solid acids such as heteropolyacid that
is a superacid and the like, treatment by column chromatography,
extraction with sulfolane, biodegradation by microbes capable of
assimilating benzene, aeration treatment utilizing volatility of
benzene, and the like.
[0048] The reaction in the first invention is typically carried out
under normal pressure and may be carried out under pressure in
order to increase the solubility of the acrylic compound in the
aqueous medium (I). In addition, the reaction temperature is not
particularly limited and preferably is in a temperature range in
which the nitrile hydratase is not deactivated and more preferably
0 to 50.degree. C. On the other hand, pH is not particularly
limited as long as the nitrile hydratase activity is maintained and
preferably is in the range of pH 5 to pH 10.
[0049] The amide-based polymer of the first invention may be
produced by homopolymerizing the amide compound obtained as
mentioned above or by copolymerizing the amide compound with at
least one unsaturated monomer copolymerizable with the amide
compound. Here, the amide compound is preferably acrylamide or
methacrylamide obtained by the production method for the amide
compound of the first invention.
[0050] The unsaturated monomers copolymerizable with an amide
compound include an unsaturated carboxylic acid such as acrylic
acid, methacrylic acid, itaconic acid, maleic acid or fumaric acid,
and a salt thereof; vinylsulfonic acid, styrene sulfonic acid,
acrylamidemethylpropane-sulfonic acid, and a salt thereof; an
alkylaminoalkyl ester of (meth)acrylic acid such as
N,N-dimethylaminoethylmethacrylate,
N,N-diethylaminoethylmethacrylate, N,N-dimethylaminoethylacrylate
or the like, and a quaternary ammonium derivative thereof;
N,N-dialkylaminoalkyl(meth)acrylamide such as
N,N-dimethylaminopropylmethacrylamide or
N,N-dimethylaminopropylacrylamide and, a quaternary ammonium
derivative thereof; a hydrophilic acrylamide such as acetone
acrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide,
N-ethylmethacrylamide, N-ethylacrylamide, N,N-diethylacrylamide,
N-propylacrylamide and the like; N-acryloylpyrrolidine,
N-acryloylpiperidine and N-acryloylmorpholine;
hydroxyethylmethacrylate, hydroxyethylacrylate,
hydroxypropylmethacrylate and hydroxypropylacrylate;
methoxypolyethyleneglycol(meth)acrylate and N-vinyl-2-pyrrolidone;
methacrylamide; an N-alkyl(meth)acrylamide derivative such as
N,N-di-n-propylacrylamide, N-n-butylacrylamide,
N-n-hexylacrylamide, N-n-hexylmethacrylamide, N-n-octylacrylamide,
N-n-octylmethacrylamide, N-tert-octylacrylamide,
N-dodecylacrylamide, N-n-dodecylmethacrylamide or the like; an
N-(.omega.-glycidoxyalkyl) (meth)acrylamide derivative such as
N,N-diglycidylacrylamide, N,N-diglycidylmethacrylamide,
N-(4-glycidoxybutyl)acrylamide, N-(4-glycidoxybutyl)methacrylamide,
N-(5-glycidoxypentyl)acrylamide, N-(6-glycidoxyhexyl)acrylamide or
the like; a (meth)acrylate derivative such as methyl(meth)acrylate,
ethyl(meth)acrylate, butyl(meth)acrylate, lauryl(meth)acrylate,
2-ethylhexyl(meth)acrylate, glycidyl(meth)acrylate or the like;
olefins such as acrylonitrile, methacrylonitrile, vinyl acetate,
vinyl chloride, vinylidene chloride, ethylene, propylene, butene
and the like; styrene, .alpha.-methylstyrene, butadiene, isoprene;
and the like.
[0051] These monomers may be used alone or two or more kinds in
combination.
[0052] The polymerization methods for these monomers include, for
example, an aqueous solution polymerization, an emulsion
polymerization and the like.
[0053] Among these, in the case of the aqueous solution
polymerization, the total concentration of the amide compound and
the optional unsaturated monomer is typically 5 to 90% by
weight.
[0054] As a polymerization initiator, for example, a radical
polymerization initiator may be used.
[0055] As the radical polymerization initiators, there may be
mentioned a peroxide such as potassium persulfate, ammonium
persulfate, hydrogen peroxide, benzoyl peroxide or the like; an
azo-based free radical initiator such as azobisisobutyronitrile,
2,2'-azobis(4-amidinopropane) dihydrochloride, sodium
4,4'-azobis(4-cyanovalerate) or the like; and a so-called redox
catalyst comprising the above-mentioned peroxides and reducing
agents such as sodium bisulfite, triethanolamine, ammonium ferrous
sulfate and the like.
[0056] The abovementioned polymerization initiators may be used
alone or two or more kinds in combination. The amount of the
polymerization initiator is typically 0.001 to 5% by weight,
relative to the total amount of the monomers.
[0057] In the case of using a single polymerization initiator, the
polymerization temperature is typically in the range of 0 to
120.degree. C. and more preferably in the range of 5 to 90.degree.
C. In addition, the polymerization temperature is not required to
be always kept constant and may be changed accordingly with the
progress of the polymerization. Since the polymerization heat will
usually generated with the progress of the polymerization to
increase the polymerization temperature, cooling may be provided as
needed.
[0058] The atmosphere during the polymerization is not particularly
limited and the polymerization is preferably carried out, for
example, under an inert gas atmosphere such as nitrogen gas and the
like, from the viewpoint of the smooth polymerization.
[0059] The polymerization time is not particularly limited and
typically is in the range of 1 to 20 hours.
[0060] In addition, the pH of the solution during the
polymerization is not particularly limited and the polymerization
may be carried out by adjusting the pH as needed. In this case,
examples of useful pH adjusters include alkalis such as sodium
hydroxide, potassium hydroxide, ammonia and the like; mineral acids
such as phosphoric acid, sulfuric acid, hydrochloric acid and the
like; organic acids such as formic acid, acetic acid and the like;
and others.
[0061] The molecular weight of the polymer obtained in the first
invention is not particularly limited and typically is in the range
of 100,000 to 50,000,000 and preferably in the range of 500,000 to
30,000,000.
[0062] The amide-based polymer of the first invention obtained in
this way has a good balance between the water solubility and the
high molecular weight, and is excellent in hue and may be
preferably used as a flocculant, an additive for manufacturing
paper, an oil recovery agent, and the like.
2. The Second Invention
[0063] Hereinafter, the second invention will be explained in
detail.
[0064] Firstly, raw materials used in the production method for the
acrylamide of the second invention are explained.
[Acrylonitrile]
[0065] In the second invention, there is used acrylonitrile having
a concentration of acrolein of 1 ppm or less. Here, the phrase
"acrylonitrile having a concentration of acrolein of 1 ppm or less"
means that the amount of acrolein contained in 1 kg of the
acrylonitrile used as a raw material of the second invention is 1
mg or less.
[0066] As methods for reducing the concentration of acrolein
contained in the acrylonitrile to 1 ppm or less, there may be
mentioned a method in which acetylacetone and the like are reacted
with acrolein in acrylonitrile and then the reaction product and
the acrylonitrile are separated by distillation and the like; a
method in which acrolein in acrylonitrile is removed by contact
with a porous ion exchange resin having a primary and/or secondary
amino group as an exchange group; and a method in which aldehydes
substantially consisting of acrolein in acrylonitrile are reduced
by contact with a weakly basic ion exchange resin of gel type
having a primary and/or secondary amino functional group.
[0067] The concentration of acrolein contained in the acrylonitrile
may be determined by a gas chromatographic method, a
high-performance liquid chromatographic method and the like.
[0068] In the second invention, the concentration of acrolein in
the acrylonitrile as a raw material is 1 ppm or less but preferably
0.5 ppm or less.
[0069] When the concentration of acrolein is within the above
range, no inhibition of reaction due to acrolein occurs with
respect to the catalytic action by the nitrile hydratase. Further,
by using the resulting acrylamide, there may be produced the
acrylamide-based polymer which is excellent in hue, has a good
balance between the water solubility and the high molecular weight,
and is also excellent in quality.
[0070] The concentration of acrolein contained in the acrylonitrile
used in the second invention is 1 ppm or less, and further the
concentration of hydrocyanic acid contained in the acrylonitrile is
preferably 5 ppm or less.
[0071] Here, the phrase "the concentration of hydrocyanic acid
contained in the acrylonitrile is 5 ppm or less" means that the
amount of hydrocyanic acid contained in 1 kg of the acrylonitrile
used as a raw material of the second invention is 5 mg or less.
[0072] As methods of reducing the concentration of hydrocyanic acid
contained in the acrylonitrile to 1 ppm or less, for example, as
described in Japanese Patent Application Laid-Open Publication No.
H11-123098, there may be mentioned a method of removing hydrocyanic
acid as a metal complex, a method using an ion exchange resin, a
method of causing hydrocyanic acid add to acrylonitrile under
alkaline conditions, and the like.
[0073] In addition, the concentration of hydrocyanic acid contained
in the acrylonitrile may be determined by a titration method using
silver nitrate after extracting the acid with an alkaline
solution.
[0074] In the second invention, the concentration of hydrocyanic
acid in the acrylonitrile is preferably 5 ppm or less, more
preferably 3 ppm or less and further more preferably 1 ppm or
less.
[0075] Further, in the second invention, the concentration of
acrolein contained in the acrylonitrile is 1 ppm or less and
additionally, it is preferable that the concentration of oxazole
contained in the acrylonitrile nitrile is 10 ppm or less.
[0076] Here, the phrase "the concentration of oxazole contained in
the acrylonitrile is 10 ppm or less" means that the amount of
oxazole contained in 1 kg of the acrylonitrile used as a raw
material of the second invention is 10 mg or less.
[0077] As a method of reducing the concentration of oxazole
contained in acrylonitrile to 10 ppm or less, there may be
mentioned, for example, a method of bringing oxazole in
acrylonitrile into contact with an H-type cation exchange resin, as
described in Japanese Patent Laid-Open Publication No.
S63-118305.
[0078] In addition, the concentration of oxazole contained in the
acrylonitrile may be determined by a gas chromatographic method, a
high-performance liquid chromatographic method and the like.
[0079] In the second invention, the concentration of oxazole in the
acrylonitrile is preferably 10 ppm or less, more preferably 5 ppm
or less and further more preferably 1 ppm or less.
[0080] Further, in the second invention, it is preferable that the
concentration of acrolein contained in the acrylonitrile used in
the second invention is within the above range and the
concentration of hydrocyanic acid is 5 ppm or less, preferably 3
ppm or less and more preferably 1 ppm or less, and the
concentration of oxazole is 10 ppm or less, preferably 5 ppm or
less and more preferably 1 ppm or less.
[Microbial Cell Containing Nitrile Hydratase and the Like]
[0081] In the second invention, the acrylamide of the second
invention may be obtained by hydrating the above acrylonitrile as a
raw material in the presence of a microbial cell containing a
nitrile hydratase or a processed product of the microbial cell and
the like as a catalyst.
[0082] In the second invention, the nitrile hydratase refers to an
enzyme having capability of hydrolyzing the nitrile compound to
produce a corresponding amide compound. Here, the microbe
containing the nitrile hydratase is not particularly limited as
long as it produces the nitrile hydratase having capability of
hydrolyzing the nitrile compound to produce a corresponding amide
compound and maintains a nitrile hydratase activity in an aqueous
solution of acrylamide.
[0083] Specifically, preferred examples of the above microbes
include microbes belonging to Nocardia, Corynebacterium, Bacillus,
thermophilic Bacillus, Pseudomonas, Micrococcus, Rhodococcus
represented by the rhodochrous species, Acinetobacter,
Xanthobacter, Streptomyces, Rhizobium, Klebsiella, Enterobacter,
Erwinia, Aeromonas, Citrobacter, Achromobacter, Agrobacterium or
Pseudonocardia represented by thermophila species.
[0084] Further, the microbes referred in the second invention also
include a transformant obtained by expressing a nitrile hydratase
gene cloned from the above-mentioned microbe in an arbitrary host.
The arbitrary hosts referred to herein are not particularly
limited, and include Escherichia coli as a representative example
as in the case of Examples described later, Bacillus such as
Bacillus subtilis and the like and other microbial strains such as
yeasts, Actinomyces and the like. Examples thereof include MT-10822
(the strain deposited at National Institute of Bioscience and Human
Technology, Agency of Industrial Science and Technology, Ministry
of International Trade and Industry, 1-3, Higashi 1-chome,
Tsukuba-shi, Ibaraki-ken, Japan on Feb. 7, 1996, under an accession
number FERM BP-5785, under the terms of the Budapest Treaty on the
International Recognition of the Deposit of Microorganisms for the
Purposes of Patent Procedure). The microbes producing the nitrile
hydratase in the second invention also include transformants
expressing a mutant nitrile hydratase that are obtained by
replacing, deleting, eliminating or inserting one or two or more of
constituent amino acids of the enzyme with other amino acids by
using recombinant DNA technology and thereby have been further
improved in amide compound resistance, nitrile compound resistance
and temperature resistance.
[0085] In producing an amide compound by using the microbe as
mentioned above, the microbial cell or the processed product of the
microbial cell is generally used. The microbial cell may be
prepared by using a general method which is well known in the
fields of molecular biology, bioengineering and genetic
engineering. For example, there may be mentioned a method in which
the microbe is planted in typical liquid culture mediums such as an
LB medium, an M9 medium and the like and then is grown at an
appropriate culture temperature (which is generally from 20 to
50.degree. C. and may be 50.degree. C. or higher in the case of a
thermophilic bacterium), and the microbe is separated and recovered
from the culture liquid using a centrifugal separation.
[0086] In addition, the processed products of the microbial cells
in the second invention include an extract and a ground product of
the above microbial cell; a post-separated product obtained by
separating and purifying a nitrile hydratase active fraction of the
extract and the ground product; and an immobilized product obtained
by immobilizing the microbial cell, or the extract, the ground
product or the post-separated product of the microbial cell using
an appropriate carrier. These are usable as the processed product
of the microbial cell of the second invention as long as they have
the nitrile hydratase activity. These may be used singly, or in
combination of two or more different kinds simultaneously or
alternately.
[Aqueous Medium]
[0087] The aqueous medium in the second invention refers to water
or an aqueous solution containing a buffer such as a phosphate or
the like, an inorganic salt such as a sulfate, carbonate or the
like, a hydroxide of alkali metal, the amide compound or the like
at a suitable concentration. Further, in the present specification,
the aqueous medium in the second invention is also referred to as
the "aqueous medium (II)".
[Reaction Conditions]
[0088] In the second invention, the concentration of the
acrylonitrile in the aqueous medium (II) at the start of the
reaction is not less than the saturated concentration of the
nitrile compound. The upper limit of the concentration is not
particularly limited, but when an overly excessive amount of the
nitrile compound is supplied, it is required to use a large amount
of the catalyst and a reactor having an excessively large volume
for completing the reaction, an excessively large heat exchanger
for removing heat, and the like. Therefore, economic burden with
respect to equipment is increased. For this reason, in the case of
acrylamide, the acrylonitrile is preferably supplied such that,
when all the acrylonitrile is converted to the corresponding
acrylamide, the theoretical concentration of acrylamide in product
solution is 40 to 80% by weight. More specifically, the
acrylonitrile is supplied in the range of 0.4 to 1.5 parts by
weight based on 1.0 part by weight of water.
[0089] In addition, the reaction time in the above reaction
possibly depends on the conditions such as the amount of the
catalyst used, the temperature and the like, and is usually in the
range of 1 to 80 hours and is preferably in the range of 2 to 40
hours.
[0090] The reactor type is not particularly limited and may be any
of a batch system, a semi-batch system and a continuous system. In
addition, the reactor type may be any of a suspended bed, a fixed
bed or a moving bed. Typically, the reaction is more preferably
carried out in a continuous-stirred tank reactor or a plug-flow
reactor, and two or more types of reactors may be used in
combination.
[0091] The amount of the catalyst to be used depends on the
reaction conditions, and the type and form of the catalyst, and is
usually 10 to 50000 ppm and preferably 50 to 30000 ppm in terms of
the weight of dry microbial cell with respect to the weight of the
reaction solution.
[0092] In addition, the hydration reaction is generally carried out
under normal pressure or pressure near normal pressure and may be
carried out under increased pressure in order to increase the
solubility of the nitrile compound in the aqueous medium (II).
Further, the reaction temperature is not particularly limited as
long as it is the freezing point or higher of the aqueous medium
(II), and the reaction is preferably carried out in the range of 0
to 50.degree. C. and more preferably of 10 to 40.degree. C.
Furthermore, the reaction may also be carried out in a slurry state
in which products are crystallized in the reaction solution. And,
the pH of the reaction solution during the hydration reaction is
not particularly limited as long as the nitrile hydratase activity
is maintained, and is preferably in the range of pH 6 to 10 and
more preferably in the range of pH 7 to 9.
[0093] In addition, an amino acid substitute maintaining the
nitrile hydratase activity may be obtained by carrying out
site-specific mutation. Similar results may be also obtained by
constructing a recombinant plasmid by a method other than the
site-specific mutation taking into account the specific mutation
site and the types of the substituted bases and then introducing
the recombinant plasmid into the host cell.
[0094] For example, the objective recombinant plasmid may be
obtained by synthesizing a DNA fragment having a DNA base sequence
in which the base sequence in the mutation site corresponds to a
desired such that base sequence to be introduced is the sequence
after the substitution of amino acids, by using a DNA synthesizer
or the like, and then substituting the fragment for a region of the
separately-isolated pPT-DB1 that corresponds to the fragment.
[Acrylamide-Based Polymer]
[0095] The acrylamide-based polymer of the second invention may be
produced by homopolymerizing the amide compound obtained as
mentioned above or by copolymerizing the acrylamide with at least
one unsaturated monomer copolymerizable with the acrylamide.
[0096] The unsaturated monomers copolymerizable with acrylamide
include an unsaturated carboxylic acid such as acrylic acid,
methacrylic acid, itaconic acid, maleic acid, fumaric acid or the
like, and a salt thereof; vinylsulfonic acid, styrene sulfonic acid
and acrylamidemethylpropane sulfonic acid, and a salt thereof; an
alkylaminoalkyl ester of (meth)acrylic acid such as
N,N-dimethylaminoethylmethacrylate,
N,N-diethylaminoethylmethacrylate, N,N-dimethylaminoethylacrylate
or the like, and a quaternary ammonium derivative thereof;
N,N-dialkylaminoalkyl(meth)acrylamide such as
N,N-dimethylaminopropylmethacrylamide,
N,N-dimethylaminopropylacrylamide or the like, and a quaternary
ammonium derivative thereof; a hydrophilic acrylamide such as
acetone acrylamide, N,N-dimethylacrylamide,
N,N-dimethylmethacrylamide, N-ethylmethacrylamide,
N-ethylacrylamide, N,N-diethylacrylamide, N-propylacrylamide and
the like; N-acryloylpyrrolidine, N-acryloylpiperidine and
N-acryloylmorpholine; hydroxyethylmethacrylate,
hydroxyethylacrylate, hydroxypropylmethacrylate and
hydroxypropylacrylate; methoxypolyethyleneglycol(meth)acrylate and
N-vinyl-2-pyrrolidone; methacrylamide; an N-alkyl(meth)acrylamide
derivative such as N,N-di-n-propylacrylamide, N-n-butylacrylamide,
N-n-hexylacrylamide, N-n-hexylmethacrylamide, N-n-octylacrylamide,
N-n-octylmethacrylamide, N-tert-octylacrylamide,
N-dodecylacrylamide, N-n-dodecylmethacrylamide or the like; an
N-(.omega.-glycidoxyalkyl) (meth)acrylamide derivative such as
N,N-diglycidylacrylamide, N,N-diglycidylmethacrylamide,
N-(4-glycidoxybutyl)acrylamide, N-(4-glycidoxybutyl)methacrylamide,
N-(5-glycidoxypentyl)acrylamide, N-(6-glycidoxyhexyl)acrylamide or
the like; a (meth)acrylate derivative such as methyl(meth)acrylate,
ethyl(meth)acrylate, butyl(meth)acrylate, lauryl(meth)acrylate,
2-ethylhexyl(meth)acrylate, glycidyl(meth)acrylate or the like;
olefins such as acrylonitrile, methacrylonitrile, vinyl acetate,
vinyl chloride, vinylidene chloride, ethylene, propylene, butene
and the like; styrene, .alpha.-methylstyrene, butadiene, isoprene
and the like.
[0097] These monomers may be used alone or two or more kinds in
combination.
[0098] The polymerization methods for these monomers include, for
example, an aqueous solution polymerization, an emulsion
polymerization and the like.
[0099] Among these, in the case of the aqueous solution
polymerization, the total concentration of acrylamide and the
optional unsaturated monomer is typically 5 to 90% by weight.
[0100] As a polymerization initiator, for example, a radical
polymerization initiator may be used.
[0101] As the radical polymerization initiators, there may be
mentioned a peroxide such as potassium persulfate, ammonium
persulfate, hydrogen peroxide, benzoyl peroxide or the like; an
azo-based free radical initiator such as azobisisobutyronitrile,
2,2'-azobis(4-amidinopropane) dihydrochloride, sodium
4,4'-azobis(4-cyanovalerate) or the like; and a so-called redox
catalysts comprising the above-mentioned peroxides and a reducing
agent such as sodium bisulfite, triethanolamine, ammonium ferrous
sulfate and the like.
[0102] The above-mentioned polymerization initiators may be used
alone or two or more kinds in combination. The amount of the
polymerization initiator is typically 0.001 to 5% by weight
relative to the total amount of the monomers.
[0103] When a single polymerization initiator is used, the
polymerization temperature is usually in the range of 0 to
120.degree. C. and preferably in the range of 5 to 90.degree. C. In
addition, the polymerization temperature is not required to be
always kept constant and may be changed accordingly with the
progress of the polymerization. Since the polymerization heat will
usually generated with the progress of the polymerization to
increase the polymerization temperature, cooling may be provided as
needed.
[0104] The atmosphere during the polymerization is not particularly
limited and the polymerization is preferably carried out, for
example, under an inert gas atmosphere such a nitrogen gas and the
like, from the viewpoint of the smooth polymerization.
[0105] The polymerization time is not particularly limited and
usually in the range of 1 to 20 hours.
[0106] In addition, the pH of the solution during the
polymerization is not particularly limited and the polymerization
may be carried out by adjusting the pH as needed. In this case,
examples of useful pH adjusters include alkalis such as sodium
hydroxide, potassium hydroxide, ammonia and the like; mineral acids
such as phosphoric acid, sulfuric acid, hydrochloric acid and the
like; organic acids such as formic acid, acetic acid and the like;
and others.
[0107] The molecular weight of the polymer obtained from the second
invention is not particularly limited and is typically in the range
of 100,000 to 50,000,000 and preferably in the range of 500,000 to
30,000,000.
[0108] The amide-based polymer of the second invention obtained in
this way has a good balance between the water solubility and the
high molecular weight and is furthermore excellent in hue, and may
be used as a flocculant, an additive for manufacturing paper, an
oil recovery agent and the like.
EXAMPLES
[0109] Hereinafter, the present invention will be explained in more
detail with reference to the Examples, but the present invention is
not limited by these Examples.
1. Examples of the First Invention
[0110] The concentration of benzene was measured according to gas
chromatographic analysis. The gas chromatographic analysis was
carried out by using G-950 1.2 mm.times.40 m (25 .mu.m)
manufactured by Chemicals Evaluation and Research Institute, Japan
as a column. Helium was used as a carrier gas and a FID detector
was used for the analysis.
[0111] In addition, the HPLC analysis in each of Examples and
Comparative Examples was carried out by using Finepak SIL
C18-5(250.times.4.6 .phi.mm) manufactured by JASCO Corporation as a
column and a 10 mM phosphoric acid aqueous solution containing 4%
by volume of acetonitrile as a developer. Further, acrylamide and
methacrylamide were detected by the absorbance at 220 nm.
Production Example 1-1
[0112] To a reaction vessel was charged an adsorbent of an
activated carbon fixed bed containing 1 kg of an activated carbon
(internal surface area: 1000 m.sup.2/kg). An acrylonitrile a having
a concentration of benzene of 26 ppm was pumped through the
adsorbent from the bottom to the top at a flow rate of 200 m/hr at
a temperature of 10.degree. C. After the acrylonitrile a passed
through the adsorbent, the concentration of benzene in the
acrylonitrile was measured to be 4.0 ppm. Hereinafter, the
acrylonitrile after the activated carbon absorption treatment is
referred to as the acrylonitrile b.
Production Example 1-2
[0113] Acrylonitrile c having a concentration of benzene of 11 ppm
was used as it is.
Production Example 1-3
[0114] Methacrylonitrile having a concentration of benzene of 8 ppm
was used as it is.
Preparation of Microbial Cell
Preparation Example 1-1
Culture of Microbial Cell Containing Nitrile Hydratase Derived from
Pseudonocardia Thermophila JCM3095
[0115] A culture medium with a volume of 100 ml having the
composition shown in the medium composition 1-1 was prepared in a
500-milliliter Erlenmeyer flask fitted with a baffle, and was
sterilized in an autoclave at 121.degree. C. for 20 minutes.
Thereafter, ampicillin was added to this medium so that the final
concentration was 50 .mu.g/ml. 30 flaskss were prepared in the same
manner. One loopful of MT-10822 strain (FERM BP-5785) was
inoculated into each Erlenmeyer flask fitted with a baffle and the
resultant medium was incubated at 37.degree. C. at 130 rpm for 20
hours. The culture solutions in Erlenmeyer flasks fitted with a
baffle were collected and only the microbial cell was separated
from the collected culture solution through centrifugation
(15000G.times.15 minutes). Subsequently, the microbial cell was
resuspended in 50 ml of a physiological saline solution and then
the wet microbial cell was obtained through recentrifugation.
[Medium Composition 1-1]
TABLE-US-00001 [0116] Yeast extract 5.0 g/liter Polypeptone 10.0
g/liter NaCl 5.0 g/liter Cobalt chloride hexahydrate 10.0 mg/liter
Ferric sulfate heptahydrate 40.0 mg/liter pH 7.5
Preparation Example 1-2
Culture of Microbial Cell Containing Nitrile Hydratase Derived from
Rhodococcus rhodochrous J-1
[0117] Wet microbial cell was obtained by using Rhodococcus
rhodochrous J-1 strain described in Japanese Unexamined Patent
Application Publication No. H06-55148 (the strain deposited at the
above-mentioned deposition agency under an accession number FERM
BP-1478, under the terms of the Budapest Treaty on the
International Recognition of the Deposit of Microorganisms for the
Purposes of Patent Procedure and is subdivided to all persons upon
request)
[0118] A culture medium with a volume of 100 ml having the
composition shown in the medium composition 1-2 was prepared into a
500-milliliter Erlenmeyer flask fitted with a baffle, and was
sterilized in an autoclave at 121.degree. C. for 20 minutes. To
this medium was inoculated one loopful of Rhodococcus rhodochrous
J-1 strain described in Japanese Patent Application Publication No.
H06-55148 (the strain deposited at the above-mentioned deposition
agency under an accession number FERM BP-1478, under the terms of
the Budapest Treaty on the International Recognition of the Deposit
of Microorganisms for the Purposes of Patent Procedure and is
subdivided to all persons upon request) and incubated at 30.degree.
C. at 130 rpm for 72 hours. Only the microbial cell was separated
from the culture solution through centrifugation (15000G.times.15
minutes) Subsequently, the microbial cell was resuspended in 50 ml
of a physiological saline solution and then the wet microbial cell
was obtained through recentrifugation.
[Culture Medium Composition 1-2]
TABLE-US-00002 [0119] Glucose 10.0 g/L Potassium dihydrogen
phosphate 0.5 g/L Dipotassium hydrogen phosphate 0.5 g/L Magnesium
sulfate heptahydrate 0.5 g/L Yeast extract 1.0 g/L Peptone 7.5 g/L
Urea 7.5 g/L Cobalt chloride hexahydrate 10.0 mg/L pH 7.2
Example 1-1
Conversion of Nitrile Compound into Amide Compound (1)
[0120] The wet microbial cell obtained in Preparation Example 1-1
was appropriately diluted with a 20 mM Tris-HCl buffer solution (pH
7.5). To the resulting solution was added the acrylonitrile b
described in Production Example 1-1 so that the concentration of
acrylonitrile in the whole reaction solution was 20% by weight and
then the resultant mixture was reacted at 20.degree. C. for 10
minutes. Here, the concentration of benzene in the aqueous medium
(I) (the whole reaction solution) was 0.8 ppm. After the reaction,
an equivalent weight of a 1 M phosphoric acid aqueous solution
based on the reaction solution was added to the reaction solution
to stop the reaction, and the concentration of the resulting
acrylamide was measured by HPLC analysis. Subsequently, the
production rate (=the reaction rate) of acrylamide per unit wet
microbial cell and per unit reaction time was calculated. The
results are shown in Table 1-1. The reaction rate obtained was set
as 100% and compared with those of Example 1-2, Example 1-3,
Comparative Example 1-1 and Comparative Example 1-2.
Example 1-2
Conversion of Nitrile Compound into Amide Compound (2)
[0121] The wet microbial cell obtained in Preparation Example 1-1
was appropriately diluted with a 20 mM Tris-HCl buffer solution (pH
7.5). To the resulting solution was added the acrylonitrile c
described in Production Example 1-2 so that the concentration of
acrylonitrile was 20% by weight and the resultant mixture was
reacted at 20.degree. C. for 10 minutes. Here, the concentration of
benzene in the aqueous medium (I) was 2.2 ppm. Thereafter, the
procedures were performed in the same manner as in Example 1-1. The
results are shown in Table 1-1.
Example 1-3
Conversion of Nitrile Compound into Amide Compound (3)
[0122] The concentration of benzene in acrylonitrile was adjusted
to be 20 ppm by adding benzene to the acrylonitrile b described in
Production Example 1-1. The procedures were performed in the same
manner as in Example 1-1 except that the acrylonitrile to be used
was replaced by the acrylonitrile as described above. Here, the
concentration of benzene in the aqueous medium (I) was 4.0 ppm. The
results are shown in Table 1-1.
Comparative Example 1-1
Conversion of Nitrile Compound into Amide Compound (1)
[0123] The procedures were performed in the same manner as in
Example 1-1 except that the acrylonitrile to be used was replaced
by the acrylonitrile a described in Production Example 1-1. Here,
the concentration of benzene in the aqueous medium (1) was 5.2 ppm.
The results are shown in Table 1-1.
Comparative Example 1-2
Conversion of Nitrile Compound into Amide Compound (2)
[0124] The concentration of benzene in acrylonitrile was adjusted
to be 26 ppm by adding benzene to the acrylonitrile b described in
Production Example 1-1. The procedures were performed in the same
manner as in Example 1-1 except that the acrylonitrile to be used
was replaced by the acrylonitrile as described above. Here, the
concentration of benzene in the aqueous medium (I) was 5.2 ppm. The
results are shown in Table 1-1.
[0125] From the Table 1-1, it is found that the decrease of
reaction rate may be prevented by controlling the concentration of
benzene in the aqueous medium (I) to 4.0 ppm or less and a
substance causing the decrease of reaction rate is benzene.
Example 1-4
Conversion of Nitrile Compound into Amide Compound (4)
[0126] The procedures were performed in the same manner as in
Example 1-1 except that the wet microbial cell to be used was
replaced by the wet microbial cell obtained in Preparation Example
1-2. The results are shown in Table 1-2. The reaction rate obtained
was set as 100% and compared with those of Example 1-5 and
Comparative Example 1-3, by setting the reaction rate obtained as
100%.
Example 1-5
Conversion of Nitrile Compound into Amide Compound (5)
[0127] The procedures were performed in the same manner as in
Example 1-3 except that the wet microbial cell to be used was
replaced by the wet microbial cell obtained in Preparation Example
1-2. The results are shown in Table 1-2.
Comparative Example 1-3
Conversion of Nitrile Compound into Amide Compound (3)
[0128] The procedures were performed in the same manner as in
Comparative Example 1-1 except that the wet microbial cell to be
used was replaced by the wet microbial cell obtained in Preparation
Example 1-2. The results are shown in Table 1-2.
Example 1-6
Conversion of Nitrile Compound into Amide Compound (6)
[0129] The wet microbial cell obtained in Preparation Example 1-1
was appropriately diluted with a 20 mM Tris-HCl buffer solution (pH
7.5). To the resulting solution was added the methacrylonitrile
described in Production Example 1-3 so that the concentration of
methacrylonitrile was 20% by weight and the resultant mixture was
reacted at 20.degree. C. for 10 minutes. Here, the concentration of
benzene in the aqueous medium (I) was 1.6 ppm. After the reaction,
an equivalent weight of a 1 M phosphoric acid aqueous solution
based on the reaction solution was added to the reaction solution
to stop the reaction, and the concentration of the resulting
methacrylamide was measured by HPLC analysis. Subsequently, the
production rate (=the reaction rate) of methacrylamide per unit wet
microbial cell and per unit reaction time was calculated. The
results are shown in Table 1-3. The reaction rate obtained was set
as 100% and compared with those of Example 1-7 and Comparative
Example 1-4.
Example 1-7
Conversion of Nitrile Compound into Amide Compound (7)
[0130] The concentration of benzene in methacrylonitrile was
adjusted to be 20 ppm by adding benzene to the methacrylonitrile
described in Production Example 1-3. The procedures were performed
in the same manner as in Example 1-6 except that the
methacrylonitrile to be used was replaced by the methacrylonitrile
as described above. Here, the concentration of benzene in the
aqueous medium (I) was 4.0 ppm. The results are shown in Table
1-3.
Comparative Example 1-4
Conversion of Nitrile Compound into Amide Compound (4)
[0131] The concentration of benzene in methacrylonitrile was
adjusted to be 25 ppm by adding benzene to the methacrylonitrile
described in Production Example 1-3. The procedures were performed
in the same manner as in Example 1-6 except that the
methacrylonitrile to be used was replaced by the methacrylonitrile
as described above. Here, the concentration of benzene in the
aqueous medium (I) was 5.0 ppm. The results are shown in Table
1-3.
Example 1-8
Conversion of Nitrile Compound into Amide Compound (8)
[0132] The procedures were performed in the same manner as in
Example 1-6 except that the wet microbial cell to be used was
replaced by the wet microbial cell obtained in Preparation Example
1-2. The results are shown in Table 1-4. The reaction rate obtained
was set as 100% and compared with those of Example 1-9 and
Comparative Example 1-5, by setting the reaction rate obtained as
100%.
Example 1-9
[0133] Conversion of Nitrile Compound into Amide Compound (9)
[0134] The procedures were performed in the same manner as in
Example 1-7 except that the wet microbial cell to be used was
replaced by the wet microbial cell obtained in Preparation Example
1-2. The results are shown in Table 1-4.
Comparative Example 1-5
Conversion of Nitrile Compound into Amide Compound (5)
[0135] The procedures were performed in the same manner as in
Comparative Example 1-4 except that the wet microbial cell to be
used was replaced by the wet microbial cell obtained in Preparation
Example 1-2. The results are shown in Table 1-4.
TABLE-US-00003 TABLE 1-1 Concentration of benzene in aqueous
Relative Reaction medium (I) (ppm) Rate (%) Example 1-1 0.8 100
Example 1-2 2.2 100 Example 1-3 4.0 84 Comparative 5.2 69 Example
1-1 Comparative 5.2 70 Example 1-2
[0136] Nitrile compound used: Acrylonitrile [0137] Microbial cell
used: Microbial cell containing the nitrile hydratase derived from
Pseudonocardia thermophila
TABLE-US-00004 [0137] TABLE 1-2 Concentration of benzene in aqueous
Relative Reaction medium (I) (ppm) Rate (%) Example 1-4 0.8 100
Example 1-5 4.0 85 Comparative 5.2 72 Example 1-3
[0138] Nitrile compound used: Acrylonitrile [0139] Microbial cell
used: Microbial cell containing a nitrile hydratase derived from
Rhodococcus rhodochrous
TABLE-US-00005 [0139] TABLE 1-3 Concentration of benzene in aqueous
Relative Reaction medium (I) (ppm) Rate (%) Example 1-6 1.6 100
Example 1-7 4.0 83 Comparative 5.0 66 Example 1-4
[0140] Nitrile compound used: Methacrylonitrile [0141] Microbial
cell used: Microbial cell containing a nitrile hydratase derived
from Pseudonocardia thermophila
TABLE-US-00006 [0141] TABLE 1-4 Concentration of benzene in aqueous
Relative Reaction medium (I) (ppm) Rate (%) Example 1-8 1.6 100
Example 1-9 4.0 85 Comparative 5.0 68 Example 1-5
[0142] Nitrile compound used: Methacrylonitrile [0143] Microbial
cell used: Microbial cell containing a nitrile hydratase derived
from Rhodococcus rhodochrous
Example 1-10
Production of Acrylamide
[0144] There were prepared a 1-liter glass flask equipped with a
stirrer as a first reactor and a Teflon (trademark) tube with an
inside diameter of 5 mm and a length of 20 m as a second reactor.
To the first reactor was charged 400 g of water in advance.
[0145] In accordance with the method described in Japanese Patent
Application Laid-Open Publication No. 2001-340091, a microbial cell
containing a nitrile hydratase was cultured and the resulting wet
microbial cell was suspended in a 0.3 mM-NaOH aqueous solution. The
suspension and the acrylonitrile b were continuously fed into the
first reactor under stirring at a rate of 49 g/h and 31 g/h,
respectively. In addition, the reaction solution was continuously
taken out from the first reactor at a rate of 80 g/h so that the
liquid level of the first reactor was maintained constant. The
liquid taken out was continuously fed into the second reactor at a
rate of 80 g/h and the reaction was further performed in the second
reactor.
[0146] Both the first and second reactors were immersed in a water
bath at a temperature of 10 to 20.degree. C. to control the liquid
temperature in each reactor at 15.degree. C.
[0147] The amount of the wet microbial cell added to the 0.3
mM-NaOH aqueous solution was adjusted so that the conversion rate
to acrylamide at the outlet of the first reactor was 90% or higher
and the concentration of acrylonitrile at the outlet of the second
reactor was at the detection limit or less (100 ppm or less) The
conversion rate to acrylamide was determined by the analysis of
HPLC.
[0148] As a result, the objective conversion rate was achieved when
the wet microbial cell was 2.5% by weight based on the 0.3 mM-NaOH
aqueous solution.
Comparative Example 1-6
[0149] The procedures were performed in the same manner as in
Example 1-10 except that the acrylonitrile to be used was replaced
by the acrylonitrile a. As a result, the added amount of the wet
microbial cell required for achieving the objective conversion rate
was 3.0% by weight of the wet microbial cell based on the 0.3
mM-NaOH aqueous solution. The added amount of the wet microbial
cell was larger than that in the case of Example 1-10 and the
inhibition of reaction by benzene was confirmed.
Comparative Example 1-7
[0150] The concentration of benzene in acrylonitrile was adjusted
to be 26 ppm by adding benzene to the acrylonitrile b. The
procedures were performed in the same manner as in Example 1-10
except that the acrylonitrile to be used was replaced by the
acrylonitrile as described above. As a result, the added amount of
the wet microbial cell required for achieving the objective
conversion rate was 3.0% by weight of the microbial cell based on
the 0.3 mM-NaOH aqueous solution. The added amount of the wet
microbial cell was larger than that in the case of Example 1-10 and
the inhibition of reaction by benzene was confirmed.
Example 1-11
[0151] The reaction solution of Example 1-10 was treated with an
activated carbon under acidic conditions (pH 5), and then the wet
microbial cell was removed. The resulting reaction solution was
neutralized with 1 N--NaOH to obtain an aqueous solution of 50% by
weight of acrylamide.
[0152] Water was added to the resulting aqueous solution of
acrylamide to obtain an aqueous solution of 20% by weight of
acrylamide. To a 1 liter polyethylene vessel was added 500 g of the
aqueous solution of 20% by weight of acrylamide and the dissolved
oxygen in the solution was removed by passing nitrogen while
maintaining the temperature at 18.degree. C., and the resulting
solution was immediately placed in a heat-insulating block made of
expanded polystyrene foam.
[0153] Subsequently, three solutions were prepared by dissolving
200.times.10.sup.-6 mpm (a molar ratio to acrylamide) of sodium
4,4'-azobis-4-cyanovalerate, 200.times.10.sup.-6 mpm of
dimethylaminopropionitrile and 80.times.10.sup.-6 mpm of ammonium
persulfate each in a small amount of water and then were promptly
poured into the 1 liter polyethylene vessel in this order. To these
reagents, a nitrogen gas had been purged in advance. During the
pouring of these reagents, and before and after the pouring of
these reagents, a small amount of the nitrogen gas was purged into
the above-mentioned polyethylene vessel to prevent an oxygen gas
from being mixed into the solution.
[0154] After an induction period of several minutes subsequent to
the pouring of the reagents, the feeding of nitrogen gas was
stopped because the internal temperature of the polyethylene vessel
was observed to rise. The polyethylene vessel was kept as it is in
the heat-insulating block for approximately 100 minutes, and
consequently the internal temperature of the polyethylene vessel
reached approximately 70.degree. C. The polyethylene vessel was
then taken out from the heat-insulating block and immersed in water
at 97.degree. C. for 2 hours to further perform the polymerization
reaction. Thereafter, the polyethylene vessel was immersed in cold
water to cool and stop the polymerization reaction.
[0155] The thus obtained water-containing gel of an acrylamide
polymer was taken out from the polyethylene vessel, divided into
small pieces, and ground through a mincer. The ground
water-containing gel of the acrylamide polymer was dried with hot
air at 100.degree. C. for 2 hours and further ground by a
high-speed rotary blade grinder to obtain a dried powderly
acrylamide polymer. The resulting dried powderly acrylamide polymer
was sieved to collect the powder that passed through 32- to 42-mesh
screens. Thus, a polymer sample for a subsequent test was
obtained.
Comparative Example 1-8
[0156] In the same manner as in Example 1-11, an aqueous solution
of 20% by weight of acrylamide was obtained from the reaction
solution obtained in Comparative Example 1-6, and a polymer sample
was obtained by using the aqueous solution of the acrylamide.
Comparative Example 1-9
[0157] In the same manner as in Example 1-11, an aqueous solution
of 20% by weight of acrylamide was obtained from the reaction
solution obtained in Comparative Example 1-7, and a polymer sample
was obtained by using the aqueous solution of the acrylamide.
<Testing Methods of Acrylamide Polymer>
[0158] The evaluations were performed on the hue of the polymer
samples obtained in the above Example 1-11, Comparative Example 1-8
and Comparative Example 1-9 by the following methods.
[0159] Water Solubility Into a 1 liter beaker was poured 600 ml of
water and 0.66 g of the polymer sample (net content: 0.6 g) was
added while the water stirring at 25.degree. C. by using a stirring
blade having a defined shape, followed by stirring at 400 rpm for 2
hours. The resulting solution was filtered through a 150-mesh metal
wire screen. The water solubility of the polymer sample was judged
from the amount of insoluble component and the filterability. In
detail, the evaluation was made as follows. Excellent: Completely
dissolved; Good: Almost completely dissolved; Do: Insoluble
component was present but separated by filtration; and Poor: The
passing of the filtrate was so slow that filtration of insoluble
component was practically impossible. Hue: With the hue of the
polymer, the polymer powders were visually evaluated.
[0160] The evaluation results are shown in Table 1-5.
TABLE-US-00007 TABLE 1-5 Concentration Hue of of benzene in Water
Polymer aqueous Solubility (Visual medium (I) of Polymer
Observation) Example 2 ppm Excellent White 1-11 Comparative 10 ppm
Do Light yellow Example 1-8 Comparative 10 ppm Do Light yellow
Example 1-9
2. Examples of the Second Invention
[0161] Hereinafter, unless otherwise specified, % and ppm are by
weight.
Example 2-1
Culture of Microbial Cell Containing Nitrile Hydratase
[0162] In accordance with the method described in Japanese Patent
Application Laid-open Publication No. 2001-340091, a microbial cell
containing a nitrile hydratase was cultured to obtain a wet
microbial cell.
[Purification of Acrylonitrile]
[0163] First, 0.3 liter of Diaion WA-20 (trade name, manufactured
by Mitsubishi Kasei Corporation), a resin having a primary and/or
secondary amino group, was washed with water. The resin was then
filled in a column made of SUS-304 having an inside diameter of 40
mm and a length of 400 mm. An acrylonitrile containing 2 ppm of
acrolein was passed through the column at a flow rate of 6 l/hr.
The concentration of acrolein in the purified acrylonitrile after
passing through the column was determined by the following
high-performance liquid chromatographic method (the lower detection
limit was 0.1 ppm) to be 0.9 ppm.
Analysis Conditions:
[0164] High-performance liquid chromatographic apparatus: LC-6A
System (Manufactured by Shimadzu Corporation) (UV detector
wavelength: 210 nm, Column temperature: 40.degree. C.)
[0165] Separation column: L-Column ODS Type-Waters (manufactured by
Chemicals Inspection and Testing Institute)
(Column Size: 4.6 Mm.times.250 Mm)
[0166] Eluent: 20% (by volume) acetonitrile aqueous solution
[0167] (Adjusted to pH 2.5 with phosphoric acid)
[Production of Acrylamide]
[0168] There were prepared a 1-liter glass flask equipped with a
stirrer as a first reactor and a Teflon (trademark) tube with an
inside diameter of 5 mm and a length of 20 m as a second reactor.
To the first reactor was charged 400 g of water in advance.
[0169] The wet microbial cell obtained by the above culture method
was suspended in a 0.3 mM-NaOH aqueous solution. The suspension and
the acrylonitrile were continuously fed into the first reactor
under stirring at a rate of 49 g/h and 31 g/h, respectively. In
addition, the reaction solution was continuously taken out from the
first reactor at a rate of 80 g/h so that the liquid level of the
first reactor was maintained constant. The liquid taken out was
continuously fed into the second reactor and the reaction was
further performed in the second reactor.
[0170] Both the first and second reactors were immersed in a water
bath at a temperature of 10 to 20.degree. C. to control the liquid
temperature in each reactor at 15.degree. C.
[0171] The added amount of the wet microbial cell to the 0.3
mM-NaOH aqueous solution was adjusted so that the conversion rate
to acrylamide at the outlet of the first reactor was 90% or more
and the concentration of acrylonitrile at the outlet of the second
reactor at the detection limit or less (100 ppm or less). The
conversion rate to acrylamide was determined by the analysis of
HPLC.
[0172] As a result, the objective conversion rate was achieved when
the wet microbial cell was 2.5% by weight based on the 0.3 mM-NaOH
aqueous solution.
Comparative Example 2-1
[0173] The procedures were performed in the same manner as in
Example 2-1 except that as a raw material, the acrylonitrile was
used without being subjected to the ion exchange treatment. As a
result, the added amount of the wet microbial cell required for
achieving the objective conversion rate was 2.8% by weight of the
wet microbial cell based on the 0.3 mM-NaOH aqueous solution. The
added amount of the wet microbial cell was larger than that in the
case of Example 2-1 and the inhibition of reaction by acrolein was
confirmed.
Comparative Example 2-2
[0174] The concentration of acrolein in acrylonitrile was adjusted
to be 2 ppm by adding acrolein to the purified acrylonitrile
obtained in Example 2-1. Acrylamide was produced using the
acrylonitrile in the same manner as in Example 2-1. As a result,
the added amount of the wet microbial cell required for achieving
the objective conversion rate was 2.8% by weight of the wet
microbial cell based on the 0.3 mM-NaOH aqueous solution. The added
amount of the wet microbial cell was larger than that in the case
of Example 2-1 and the inhibition of reaction by acrolein was
confirmed.
Comparative Example 2-2
[0175] The reaction solution of Example 2-1 was treated with
activated carbon under acidic conditions (pH 5), and then the wet
microbial cell was removed. The resulting reaction solution was
neutralized with 1 N--NaOH to obtain an aqueous solution of 50% by
weight of acrylamide.
[0176] Water was added to the resulting acrylamide solution to
obtain an aqueous solution of 20% by weight of acrylamide. To a 1
liter polyethylene vessel was added 500 g of the aqueous solution
of 20% by weight of acrylamide and the dissolved oxygen in the
solution was removed by passing nitrogen while maintaining the
temperature at 18.degree. C. and the resulting solution was
immediately placed in a heat-insulating block made of expanded
polystyrene foam.
[0177] Subsequently, three solutions were prepared by dissolving
200.times.10.sup.-6 mpm (a molar ratio to acrylamide) of sodium
4,4'-azobis-4-cyanovalerate, 200.times.10.sup.-6 mpm of
dimethylaminopropionitrile and 80.times.10.sup.-6 mpm of ammonium
persulfate each in a small amount of water and then were promptly
poured into the 1 liter polyethylene vessel in this order. To these
reagents, a nitrogen gas had been purged in advance. During the
pouring of these reagents, and before and after the pouring of
these reagents, a small amount of the nitrogen gas was purged into
the above-mentioned polyethylene vessel to prevent an oxygen gas
from being mixed into the solution.
[0178] After an induction period of several minutes subsequent to
the pouring of the reagents, the feeding of nitrogen gas was
stopped because the internal temperature of the polyethylene vessel
was observed to rise. The polyethylene vessel was kept as it is in
the heat-insulating block for approximately 100 minutes, and
consequently the internal temperature of the polyethylene vessel
reached approximately 70.degree. C. The polyethylene vessel was
then taken out from the heat-insulating block and immersed in water
at 97.degree. C. for 2 hours to further perform the reaction.
Thereafter, the polyethylene vessel was immersed in cold water to
cool and stop the polymerization reaction.
[0179] The thus obtained water-containing gel of an acrylamide
polymer was taken out from the polyethylene vessel, divided into
small pieces, and ground through a mincer. The ground
water-containing gel of the acrylamide polymer was dried with hot
air at 100.degree. C. for 2 hours and further ground by a
high-speed rotary blade grinder to obtain a dried powderly
acrylamide. The resulting dried powderly acrylamide polymer was
sieved to collect the powder that passed through 32- to 42-mesh
screens. Thus, a polymer sample for a subsequent test was
obtained.
Example 2-3
[0180] The purified acrylonitrile used in Example 2-1 was further
passed through a column made of SUS-304 having an inside diameter
of 40 mm and a length of 400 mm in which 0.3 liter of Diaion WA-20
washed with water was filled at a flow rate of 6 l/hr. The
concentration of acrolein in the purified acrylonitrile after
passing through the column was 0.4 ppm.
[0181] An aqueous solution of 20% by weight of acrylamide was
obtained using the acrylonitrile in the same manner as in Example
2-1 and Example 2-2, and a polymer sample was obtained by using the
aqueous solution of the acrylamide.
Comparative Example 2-3
[0182] An aqueous solution of 20% by weight of acrylamide was
obtained from the reaction solution obtained in Comparative Example
2-1 in the same manner as in Example 2-2, and a polymer sample was
obtained by using the aqueous solution of the acrylamide.
Comparative Example 2-4
[0183] An aqueous solution of 20% by weight of acrylamide was
obtained from the reaction solution obtained in Comparative Example
2-2 in the same manner as in Example 2-2, and a polymer sample was
obtained by using the aqueous solution of the acrylamide.
<Testing Methods of Acrylamide Polymer>
[0184] For the polymer samples obtained in the above Example 2-2,
Example 2-3 and Comparative Example 2-2, the evaluation of water
solubility, measurement of the standard viscosity and evaluation of
hue were performed using the following methods.
[0185] Water Solubility Into an 1 liter beaker was placed 600 ml of
water and 0.66 g of the polymer sample (net content: 0.6 g) was
added while the water stirring at 25.degree. C. by using a stirring
blade having a defined shape, followed by stirring at 400 rpm for 2
hours. The resulting solution was filtered through a 150-mesh metal
wire screen. The water solubility of the polymer sample was judged
from the amount of insoluble component and the filterability. In
detail, the evaluation was made as follows. Excellent: Completely
dissolved; Good: Almost completely dissolved; Do: Insoluble
component was present but separated by filtration; and Poor: The
passing of the filtrate was so slow that filtration of insoluble
component was practically impossible.
[0186] Standard viscosity: The filtrate obtained in the above water
solubility test was an aqueous polymer solution having a
concentration of 0.1% by weight. To the aqueous polymer solution
was added sodium chloride with a concentration equivalent to 1 M.
By using a BL-type viscometer equipped with a BL adapter, the
viscosity (standard viscosity) of the resulting solution was
measured at 25.degree. C. and a rotor revolution speed of 60 rpm.
The standard viscosity obtained in this manner is commonly employed
as a value correlated with the molecular weight.
[0187] Hue: With the hue of the polymer, the polymer powders were
visually evaluated.
[0188] The evaluation results are shown in Table 2-1.
TABLE-US-00008 TABLE 2-1 Water Viscosity of Concentration Solu-
Polymer Hue of of Acrolein in bility Aqueous Polymer Raw Material
of Solution (Visual Acrylonitrile Polymer (mPa s) Observation)
Example 2-2 0.9 ppm Good 5.8 White Example 2-3 0.4 ppm Excel- 5.8
White lent Comparative 2 ppm Poor No Light Yellow Example 2-3
measurement done* Comparative 2 ppm Poor No Light Yellow Example
2-4 measurement done* *The viscosity of the filtrate is impossible
to be measured because the passing of the filtrate was slow and the
filtration was practically impossible.
INDUSTRIAL APPLICABILITY
[0189] According to the first invention, since a corresponding
amide compound may be efficiently produced from a nitrile compound
by the reaction using a nitrile hydratase, the present invention is
useful for industrially performing the production of the amide
compound.
* * * * *