U.S. patent application number 13/808670 was filed with the patent office on 2013-05-02 for anti-corrosive agent for washing of metal with acid, detergent solution composition, and method for washing of metal.
This patent application is currently assigned to NITTO BOSEKI CO., LTD.. The applicant listed for this patent is Yasuhito Nakata, Hiroyuki Takayama. Invention is credited to Yasuhito Nakata, Hiroyuki Takayama.
Application Number | 20130109607 13/808670 |
Document ID | / |
Family ID | 45469279 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130109607 |
Kind Code |
A1 |
Takayama; Hiroyuki ; et
al. |
May 2, 2013 |
ANTI-CORROSIVE AGENT FOR WASHING OF METAL WITH ACID, DETERGENT
SOLUTION COMPOSITION, AND METHOD FOR WASHING OF METAL
Abstract
An anti-corrosive agent for washing of a metal with an acid,
which comprises an amphoteric polymeric compound (P) having at
least one cationic constituent unit (A) having a specific
structure, at least one anionic constituent unit (B) having a
specific structure and a specific sulfur-containing constituent
unit (C).
Inventors: |
Takayama; Hiroyuki;
(Koriyama-shi, JP) ; Nakata; Yasuhito;
(Koriyama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Takayama; Hiroyuki
Nakata; Yasuhito |
Koriyama-shi
Koriyama-shi |
|
JP
JP |
|
|
Assignee: |
NITTO BOSEKI CO., LTD.
Fukushima-shi, Fukushima
JP
|
Family ID: |
45469279 |
Appl. No.: |
13/808670 |
Filed: |
June 20, 2011 |
PCT Filed: |
June 20, 2011 |
PCT NO: |
PCT/JP2011/064025 |
371 Date: |
January 7, 2013 |
Current U.S.
Class: |
510/259 ;
134/3 |
Current CPC
Class: |
C23G 1/061 20130101;
C11D 3/3796 20130101; C11D 7/08 20130101; C11D 3/0073 20130101;
C23G 1/065 20130101; C23G 1/06 20130101; C23G 1/088 20130101; C11D
7/265 20130101; C11D 11/0029 20130101; C23F 11/173 20130101 |
Class at
Publication: |
510/259 ;
134/3 |
International
Class: |
C23G 1/06 20060101
C23G001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2010 |
JP |
2010-160164 |
Claims
1. An anti-corrosive agent for washing of a metal with an acid,
comprising an amphoteric polymer compound (P) having: at least one
cationic constituent unit (A) having a structure represented by the
following structural formula (Ia) or (Ib), a structure corresponds
to an inorganic acid salt or an organic acid salt thereof or a
structure represented by the following structural formula (IIa) or
formula (IIb): ##STR00012## wherein R.sup.1 in formulae (Ia) and
(Ib), above, is hydrogen atom, methyl group, ethyl group, or benzyl
group; R.sup.2 and R.sup.3 in formulae (IIa) and (IIb), above, each
independently are hydrogen atom, methyl group, ethyl group, or
benzyl group; and X.sup.- in formulae (IIa) and (IIb), above, is a
counter ion; at least one anionic constituent unit (B) represented
by the following structural formula (III), (IV) or (V):
##STR00013## wherein R.sup.4 in formula (III), above, is hydrogen
or methyl group; and Y in formulae (III), (IV) and (V) each
independently are hydrogen, Na, K, NH.sub.4, 1/2Ca, 1/2Mg, 1/2Fe,
1/3Al, or 1/3Fe for each carboxy group to which they are bonded);
and a constituent unit (C) represented by the following structural
formula (VI): ##STR00014##
2. The anti-corrosive agent according to claim 1, wherein the
counter ion X.sup.- is an anion derived from an organic acid or an
inorganic acid.
3. The anti-corrosive agent according to claim 1, wherein at least
a part of the cationic constituent unit (A) is derived from a
cationic monomer selected from the group consisting of
diallylamines and inorganic acid salts and organic acid salts
thereof.
4. The anti-corrosive agent according to claim 1, wherein at least
a part of the cationic constituent unit (A) is derived from
diallyldimethylammonium chloride and at least a part of the anionic
constituent unit (B) is derived from maleic acid.
5. An anti-corrosive agent for washing of a metal with an acid,
comprising an amphoteric polymer compound (F) obtainable by
copolymerizing: at least one monomer (a) having a structure
represented by the following structural formula (VII), a
corresponds to an inorganic acid salt or an organic acid salt
thereof or a structure represented by the following structural
formula (VIII): ##STR00015## wherein R.sup.5 in formula (VII),
above, is hydrogen atom, methyl group, ethyl group, or benzyl
group; R.sup.6 and R.sup.7 in formula (VIII), above, each
independently are hydrogen atom, methyl group, ethyl group, or
benzyl group; and Z.sup.- in formula (VIII), above, is a counter
ion); at least one monomer (.beta.) selected from the group
consisting itaconic acid, citraconic acid, mesaconic acid, maleic
acid, fumaric acid, methylenemalonic acid, and compounds in which
the hydrogens in the carboxyl groups in these acids are entirely or
partially substituted with at least one species selected from the
group consisting of Na, K, NH.sub.4, 1/2Ca, 1/2Mg, 1/2Fe, 1/3Al,
and 1/3Fe; and sulfur dioxide.
6. A detergent solution composition comprising an acid solution and
an anti-corrosive agent according to claim 1, wherein the content
of the amphoteric polymer compound (P) or the amphoteric polymer
compound (P') is 0.1 to 50000 mg based on 1 L of the acid
solution.
7. A method for washing a metal, characterized in that the
detergent solution composition according to claim 6 is sprayed to
the surface of the metal or the surface of the metal is immersed in
the detergent solution composition to carryout the washing.
8. A detergent solution composition comprising an acid solution and
an anti-corrosive agent according to claim 5, wherein the content
of the amphoteric polymer compound (P) or the amphoteric polymer
compound (P') is 0.1 to 50000 mg based on 1 L of the acid
solution.
9. A method for washing a metal, characterized in that the
detergent solution composition according to claim 8 is sprayed to
the surface of the metal or the surface of the metal is immersed in
the detergent solution composition to carryout the washing.
Description
TECHNICAL FIELD
[0001] The present invention relates to an anti-corrosive agent for
washing of a metal with an acid that is excellent in anti-corrosion
effect and stability and its applications.
BACKGROUND ART
[0002] Surfaces of the metals such as metal steel sheets have black
oxide coating such as mill scale adhering thereon. For this reason,
when a treatment such as an anti-corrosive treatment and plating is
performed on metal steel sheet or the like in order to improve the
performance of the final product, it is widely performed that the
oxide coating is removed before the treatment, thereby giving
anti-corrosiveness uniformly onto the surface of the steel sheet or
improving adhesion between the surface of the steel sheet and
plating coating or the like.
[0003] To remove scale or rust, acid washing using an acid
detergent solution for a metal (hereinafter, also referred to as an
"acid solution") is usually performed. Examples of the acid
detergent solution for a metal include aqueous solutions of
inorganic acids such as sulfuric acid, hydrochloric acid and nitric
acid; organic acids such as phosphoric acid, sulfamic acid,
hydrofluoric acid, oxalic acid, citric acid, glycolic acid and
formic acid; chelating agents such as ethylenediaminetetraacetic
acid and mixtures thereof. As scale, rust and so on usually
extremely strongly adhere to the surface of metal, the acid washing
using the acid detergent solution for the metal needs a
considerably long time to completely remove them. Moreover, when
the acid washing is performed, not only the scale and rust but also
the metallic substrate is dissolved and corroded. In this view,
anti-corrosive agents to be added to the acid have been used in
order to solve such a problem. For example, nitrogen-containing
organic compounds are representative examples of such
anti-corrosive agents.
[0004] As the nitrogen-containing organic compound used as an
anti-corrosive agent, quaternary ammonium salts are known (for
example, see Patent Document 1). As such quaternary ammonium salts,
1-vinyl-3-ethylimidazolinium bromide, 3-ethylbenzothiazolium
bromide, ethyltriethanolammonium bromide and the like are used. It
is known that, in addition to these quaternary ammonium salts, a
nitrogen-containing organic compound other than the quaternary
ammonium salts is concurrently used. For example,
hexamethylenetetramine can be used (Patent Document 1). Such a
nitrogen-containing organic compound has a detrimental effect of
reducing the acid washing rate. Accordingly, when a
nitrogen-containing organic compound of these is contained in an
acid detergent solution for a metal, the acid washing time becomes
further longer, and the deterioration in working efficiency cannot
be avoided. Also, the anti-corrosion effect thereof is not
sufficiently satisfying.
[0005] As the nitrogen-containing organic compound acting as the
anti-corrosive agent, thiourea and derivatives thereof have also
been proposed (for example, see Patent Document 2). Unfortunately,
thiourea and derivatives thereof also have drawbacks similar to
those of the quaternary ammonium salts.
[0006] Meanwhile, as the nitrogen-containing organic compound
acting as an anti-corrosive agent, homopolymers of quaternary
ammonium salt-substituted vinyl compounds and cationic polymers
such as polyamine compounds having a cationic constituent unit and
a sulfur dioxide unit (for example, see Patent Document 3) are
known. Among these, the polyamine compounds have an anti-corrosion
effect higher than that of the conventional nitrogen-containing
organic compound, and are useful as an additive for the acid
detergent solution for a metal, However, attempts to shorten the
acid washing time for the efficiency in the acid washing have been
made recently. For this reason, the content of the acid in the acid
detergent solution for a metal has been increased, and therefore
development of an anti-corrosive agent having a higher
anti-corrosion effect has been demanded.
[0007] Moreover, in order to suppress the corrosion effectively,
usage of a plurality of anti-corrosive agents for a metal in
combination can be considered. In this case, the concentration
ratio among the respective anti-corrosive agents changes along with
the progress of the usage, and the anti-corrosion effect is likely
to change, which may lead to fluctuation in the property of the
final products.
[0008] Moreover, the copolymers having a cationic constituent unit
and a sulfur dioxide unit currently in use may also change in the
anti-corrosion effect as the concentration thereof changes. So, if
the concentration of the anti-corrosive agent contained in the acid
detergent solution for a metal using such a copolymer changes over
the time, the problem of the fluctuation in the property of the
final products may be caused therefrom.
CITATION LIST
Patent Literature
[0009] Patent Document 1: JP 61-037988 A
[0010] Patent Document 2: JP 11-050280 A
[0011] Patent Document 3: JP 2000-96049 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0012] In consideration of background arts, above, the present
inventors attempted to develop an anti-corrosive agent for washing
of a metal with an acid in which an anti-corrosion effect is high
in acid washing of a surface of a metal, and change in an
anti-corrosion effect is small even if the concentration of the
anti-corrosive agent changes. As a result, unexpectedly, it was
found that the problem can be solved by using an amphoteric polymer
compound having a specific cationic constituent unit, a specific
anionic constituent unit, and a constituent unit derived from
sulfur dioxide. Namely, an object of the present invention is to
provide an anti-corrosive agent for washing of a metal with an acid
in which an anti-corrosion effect is high in acid washing of a
surface of a metal, and change in an anti-corrosion rate is small
even if the concentration of the anti-corrosive agent changes.
MEANS FOR SOLVING THE PROVLEMS
[0013] Namely, the present invention relates to any of (1) to (7)
below:
(1) An anti-corrosive agent for washing of a metal with an acid,
comprising an amphoteric polymer compound (P) having:
[0014] at least one cationic constituent unit (A) having a
structure represented by the following structural formula (Ia) or
(Ib), a structure corresponds to an inorganic acid salt or an
organic acid salt thereof or a structure represented by the
following structural formula (IIa) or (IIb):
##STR00001##
wherein R.sup.1 in formulae (Ia) and (Tb), above, is hydrogen atom,
methyl group, ethyl group, or benzyl group; R.sup.2 and R.sup.3 in
formulae (IIa) and (IIb), above, each independently are hydrogen
atom, methyl group, ethyl group, or benzyl group; and X.sup.- in
formulae (IIa) and (IIb), above, is a counter ion;
[0015] at least one anionic constituent unit (B) represented by the
following structural formula (III), (IV) or (V):
##STR00002##
wherein R.sup.4 in formula (III), above, is hydrogen or methyl
group; and Y in formulae (III), (IV) and (V), above, each
independently are hydrogen, Na, K, NH.sub.4, 1/2Ca, 1/2Mg, 1/2Fe,
1/3Al, or 1/3Fe for each carboxy group to which they are bonded;
and
[0016] a constituent unit (C) represented by the following
structural formula (VI):
##STR00003##
(2) The anti-corrosive agent according to (1), wherein the counter
ion X.sup.- is an anion derived from an organic acid or an
inorganic acid. (3) The anti-corrosive agent according to (1),
wherein at least a part of the cationic constituent unit (A) is
derived from a cationic monomer selected from the group consisting
of diallylamines and inorganic acid salts and organic acid salts
thereof. (4) The anti-corrosive agent according to (1), wherein at
least a part of the cationic constituent unit (A) is derived from
diallyldimethylammonium chloride and at least part of the anionic
constituent unit (B) is derived from maleic acid. (5) An
anti-corrosive agent for washing of a metal with an acid,
comprising an amphoteric polymer compound (P') obtainable by
copolymerizing:
[0017] at least one monomer (.alpha.) having a structure
represented by the following structural formula (VII), a structure
corresponding to an inorganic acid salt or an organic acid salt
thereof or a structure represented by the following structural
formula (VIII):
##STR00004##
wherein R.sup.5 in formula (VII), above, is hydrogen atom, methyl
group, ethyl group, or benzyl group; R.sup.6 and R.sup.7 in formula
(VIII), above, each independently are hydrogen atom, methyl group,
ethyl group, or benzyl group; and Z.sup.- in formula (VIII), above,
is a counter ion);
[0018] at least one monomer (.beta.) selected from the group
consisting of itaconic acid, citraconic acid, mesaconic acid,
maleic acid, fumaric acid, methylenemalonic acid and compounds in
which the hydrogens in the carboxyl groups in these acids are
entirely or partially substituted with at least one species
selected from the group consisting of Na, K, NH4, 1/2Ca, 1/2Mg,
1/2Fe, 1/3Al, and 1/3Fe; and
[0019] sulfur dioxide.
(6) A detergent solution composition comprising an acid solution
and an anti-corrosive agent according to any one of (1) to (5),
wherein the content of the amphoteric polymer compound (P) or the
amphoteric polymer compound (P') is 0.1 to 50000 mg based on 1 L of
the acid solution. (7) A method for washing a metal, characterized
in that the detergent solution composition according to (6) is
sprayed to the surface of the metal or the surface of the metal is
immersed in the detergent solution composition to carry out the
washing.
ADVANTAGES OF THE INVENTION
[0020] The anti-corrosive agent for washing of a metal with an acid
according to the present invention can effectively suppress
corrosion of a metal when the surface of the metal is acid washed.
Additionally, in the anti-corrosive agent for washing of a metal
with an acid according to the present invention, change in the
anti-corrosion rate is extremely small even if the concentration of
the anti-corrosive agent changes, and therefore quality of the
final product can easily be kept constant, As a result, the
anti-corrosive agent for washing of a metal with an acid according
to the present invention makes great contribution to the
development of a variety of industries such as the field of metal
industries.
DESCRIPTION OF EMBODIMENTS
[0021] Amphoteric Polymer Compound (P)
[0022] A first anti-corrosive agent for washing of a metal with an
acid according to the present invention comprises an amphoteric
polymer compound (P) having:
[0023] at least one cationic constituent unit (A) having a
structure represented by the following structural formula (Ia) or
(Ib), a structure corresponding to an inorganic acid salt or an
organic acid salt thereof or a structure represented by the
following structural formula (IIa) or (IIb):
##STR00005##
wherein R.sup.1 in formulae (Ia) and (Ib), above, is hydrogen atom,
methyl group, ethyl group, or benzyl group; R.sup.2 and R.sup.3 in
formulae (IIa) and (IIb), above, each independently are hydrogen
atom, methyl group, ethyl group, or benzyl group; and X.sup.- in
formulae (IIa) and (IIb), above, is a counter ion;
[0024] at least one anionic constituent unit (B) represented by the
following structural formula (III), (IV) or (V):
##STR00006##
wherein R.sup.4 in formula (III), above, is hydrogen or methyl
group and Y in formulae (III), (IV) and (V) each independently are
hydrogen, Na, K, NH.sub.4, 1/2Ca, 1/2Mg, 1/2Fe, 1/3Al, or 1/3Fe for
each carboxy group to which they are bonded; and
[0025] a constituent unit (C) represented by the following
structural formula (VI):
##STR00007##
[0026] Here, "comprise" is used with an intention that the term
includes both cases that the entirety of the first anti-corrosive
agent for washing of a metal with an acid according to the present
invention is constituted of the amphoteric polymer compound (P) and
that a part of the first anti-corrosive agent for washing of a
metal with an acid according to the present invention is
constituted of the amphoteric polymer compound (P).
[0027] As long as the advantageous effects of the present invention
are not impaired, the amphoteric polymer compound (P) used in the
present invention may include a fourth constituent unit that is a
constituent unit not corresponding to any of the cationic
constituent unit (A), the anionic constituent unit (B) and the
constituent unit (C), a constituent unit derived from a monomer
such as monoallylamine and acrylamide for example. The constituent
unit derived from a monomer such as monoallylamine and acrylamide
may be included in a proportion of 15 mol % or less, preferably 10
mol % or less, and more preferably 5 mol % or less based on the
total constituent units, for example.
[0028] In the amphoteric polymer compound (P), the molar ratio of
cationic constituent units (A)/anionic constituent units (B) in the
copolymerization is preferably 10/1 to 1/3, more preferably 8/1 to
1/2, and particularly preferably 6/1 to 1/1. In the amphoteric
polymer compound (P), the molar ratio of the cationic constituent
unit (A)/constituent unit derived from sulfur dioxide (C) in the
copolymerization is preferably 1/1 to 1/0.01, more preferably 1.1/1
to 1/0.025, and particularly preferably 1.3/1 to 1/0.05.
Furthermore, in the amphoteric polymer compound (P), the
copolymerization ratio of the anionic constituent unit
(B)/constituent unit derived from sulfur dioxide (C) is preferably
20/1 to 1/20, more preferably 15/1 to 1/15, and particularly
preferably 10/1 to 1/10. The amphoteric polymer compound (P)
usually has a molecular weight of 1,000 to 10,000,000, preferably
3,000 to 1,000,000, more preferably 5,000 to 100,000, still more
preferably 10,000 to 50,000, and particularly preferably 15,000 to
30,000.
[0029] Cationic Constituent Unit (A)
[0030] The cationic constituent unit (A) that constitutes the
amphoteric polymer compound (P) used in the present invention has a
structure represented by the following structural formula (Ia) or
(Ib), a structure corresponding to an inorganic acid salt or an
organic acid salt thereof or a structure represented by the
following structural formula (IIa) or (IIb).
##STR00008##
wherein R.sup.- in formulae (Ia) and (Ib), above, is hydrogen atom,
methyl group, ethyl group, or benzyl group; R.sup.2 and R.sup.3 in
formulae (IIa) and (IIb), above, each independently are hydrogen
atom, methyl group, ethyl group, or benzyl group and X in formulae
(IIa) and (IIb), above, is a counter ion. X.sup.- is preferably an
anion derived from an organic acid or an inorganic acid, and
particularly preferably a halogen ion (more preferably, Cl.sup.-,
Br.sup.-, or I.sup.-), methylsulfuric acid ion, ethylsulfuric acid
ion or acetate ion.
[0031] At least a part of the cationic constituent unit (A) is
preferably derived from a cationic monomer selected from the group
consisting of diallylamines and inorganic acid salts and organic
acid salts thereof. At least a part of the cationic constituent
unit (A) is particularly preferably a constituent unit derived from
diallyldimethylammonium chloride.
[0032] In the amphoteric polymer compound (P), a single species of
the cationic constituent unit (A) may solely be used, and more than
one species of the cationic constituent units (A) each having a
different structure may be used in combination.
[0033] In the case where more than one species of the cationic
constituent units (A) each having a different structure are used in
combination, each of the cationic constituent units may have
different structures within the scope represented by the same
general structural formula (Ia), (Ib), (IIa), or (IIb), or may have
structures from different each other represented by different
general structural formulae. In the former case, for example, more
than one species of cationic constituent units (A) each represented
by general structural formula (Ia) and having a different structure
attributed to the difference in the structure of R.sup.- may be
used in combination. In the latter case, for example, one cationic
constituent unit (A) having a structure represented by structural
formula (Ia), and another cationic constituent unit (A) having a
structure represented by structural formula (IIa) may be used.
[0034] while the content of the cationic constituent unit (A) in
the amphoteric polymer compound (P) is not particularly limited,
the content preferably is an amount corresponding to the
copolymerization molar ratio.
[0035] Anionic Constituent Unit (B)
[0036] The anionic constituent unit (B) that constitutes the
amphoteric polymer compound (P) used in the present invention has a
structure represented by the following structural formula (III),
(IV), or (V).
##STR00009##
wherein R.sup.4 in formula (III), above, is hydrogen or methyl
group; and Y in formulae (III), (IV) and (V), above, each
independently is hydrogen, Na, K, NH.sub.4, 1/2Ca, 1/2Mg, 1/2Fe,
1/3Al, or 1/3Fe for each carboxy group to which they are
bonded,.
[0037] In the amphoteric polymer compound (P), a single species of
the anionic constituent unit (B) may solely be used, and more than
one species of the anionic constituent units (B) each having a
structure different from each other may be used in combination.
[0038] In the case where more than one species of the anionic
constituent units (B) each having a structure different from each
other are used in combination, each of the anionic constituent
units may have a different structure within the scope represented
by the same structural formula (III), (IV), or (V), or may have
structures deferent from each other represented by different
general structural formulae. In the former case, for example, more
than one species of anionic constituent units (B) each represented
by the formula (III) and having a different structure attributed to
the difference in the element of Y may be used in combination. In
the latter case, for example, one anionic constituent unit (B)
having a structure represented by structural formula (III) and
another anionic constituent unit (B) having a structure represented
by structural formula (IV) may be used.
[0039] At least a part of the anionic constituent unit (B) is
preferably derived from maleic acid. In this case, the anionic
constituent unit (B) has a structure represented by the formula
(IV) in which both Y are hydrogen.
[0040] While the content of the anionic constituent unit (B) in the
amphoteric polymer compound (P) is not particularly limited, the
content preferably is an amount corresponding to the aforementioned
molar ratio in copolymerization.
[0041] Constituent Unit (C)
[0042] The constituent unit (C) that constitutes the amphoteric
polymer compound (P) used in the present invention has a structure
represented by the formula (VI):
##STR00010##
[0043] Usually, the constituent unit (C) can be introduced into the
polymer by using sulfur dioxide as a monomer. While the content of
the constituent unit (C) in the amphoteric polymer compound (P) is
not particularly limited, it preferably is an amount corresponding
to the aforementioned molar ratio the in copolymerization.
[0044] Usually, the amphoteric polymer compound (P) can be produced
by copolymerizing a cationic monomer (.alpha.), an anionic monomer
(.beta.), described later, and sulfur dioxide. In this case, the
copolymerization is quantitatively performed, and therefore the
copolymerization ratio of the aforementioned constituent units (A),
(B) and (C) is substantially the same as the ratio of the monomers
(.alpha.), (.beta.) and sulfur dioxide as charged.
[0045] Cationic Monomer (a)
[0046] In the production of the amphoteric polymer compound (P)
used in the present invention, a specific cationic monomer (a) can
be used to introduce the cationic constituent unit (A).
[0047] The cationic monomer (.alpha.) has a structure represented
by the following structural formula (VII), a structure
corresponding to an inorganic acid salt or an organic acid salt
thereof or a structure represented by the following structural
formula (VIII):
##STR00011##
wherein R.sup.5 in formula (VII), above, is hydrogen atom, methyl
group, ethyl group, or benzyl group; R.sup.6 and R.sup.7 in formula
(VIII), above, each independently are hydrogen atom, methyl group,
ethyl group, or benzyl group; and Z.sup.- in formula (VIII), above,
is a counter ion.
[0048] More specifically, examples of the cationic monomer
(.alpha.) include diallylamines such as diallylamine, N-hydrocarbon
group-substituted diallylamines and diallyldialkylammonium salts
(namely, compounds having a diallylamine skeleton).
Diallyldialkylammonium salts are preferable because the
anti-corrosive agent is easily dissolved in the acid solution, and
therefore the acid detergent solution composition can easily be
prepared.
[0049] Examples of the N-hydrocarbon group-substituted
diallylamines used in the present invention include
N-methyldiallylamine, N-ethyldiallylamine and
N-benzyldiallylamine.
[0050] In the case where the cationic monomer (.alpha.) is
diallylamine or N-hydrocarbon group-substituted diallylamines, an
inorganic acid salt, such as hydrochloric acid salts, sulfuric acid
salts, nitric acid salts, and phosphoric acid salts, and an organic
acid, salt such as acetic acid salts, of each amines may be used as
a starting monomer for the copolymerization.
[0051] Examples of the diallyldialkylammonium salts used in the
present invention include, but not limited to, chlorinated
diallyldimethylammonium (diallyldimethylammonium chloride),
diallyldimethylammonium bromide, diallyldimethylammonium iodide,
diallyldimethylammonium methyl sulfate, diallyldimethylammonium
ethyl sulfate, diallyldiethylammonium chloride,
diallyldiethylammonium bromide, diallyldiethylammonium iodide,
diallyldiethylammonium methyl sulfate, diallyldiethylammonium ethyl
sulfate, diallylethylmethylammonium chloride,
diallylethylmethylammonium bromide, diallylethylmethylammonium
iodide, diallylethylmethylammonium methyl sulfate,
diallylethylmethylammonium ethyl sulfate,
diallylmethylbenzylammonium chloride, diallylmethylbenzylammonium
bromide, diallylmethylbenzylammonium iodide,
diallylmethylbenzylammonium methyl sulfate,
diallylmethylbenzylammonium ethyl sulfate,
diallylethylbenzylammonium chloride, diallylethylbenzylammonium
bromide, diallylethylbenzylammonium iodide,
diallylethylbenzylammonium methyl sulfate,
diallylethylbenzylammonium ethyl sulfate, diallyldibenzylammonium
chloride, diallyldibenzylammonium bromide, diallyldibenzylammonium
iodide, diallyldibenzylammonium methyl sulfate, and
diallyldibenzylammonium ethyl sulfate. Namely, in the formula
(VIII), above, the combination of the groups R.sup.6 and R.sup.7 is
preferably dimethyl, diethyl, ethylmethyl, dibenzyl, methylbenzyl,
or ethylbenzyl, and the counter ion Z.sup.- is preferably a halogen
ion, methylsulfuric acid ion, or ethylsulfuric acid ion, though is
not limited thereto.
[0052] Anionic Monomer (.beta.)
[0053] In production of the amphoteric polymer compound (P) used in
the present invention, anionic monomer (.beta.) can be used to
introduce the anionic constituent unit (B).
[0054] The anionic monomer (.beta.) is a monomer selected from the
group consisting of itaconic acid, citraconic acid, mesaconic acid,
maleic acid, fumaric acid, and methylenemalonic acid, and compounds
in which the hydrogens in the carboxyl groups in these acids are
entirely or partially substituted with at least one species
selected from the group consisting of Na, K, NH.sub.4, 1/2Ca,
1/2Mg, 1/2Fe, 1/3Al, and 1/3Fe.
[0055] More preferably, as the anionic monomer (.beta.), fumaric
acid, maleic acid, citraconic acid, itaconic acid, a sodium salt
thereof, a potassium salt thereof, an ammonium salt thereof or the
like can be used.
[0056] Among the amphoteric polymer compounds (P) used in the
present invention, a particularly preferable amphoteric polymer
compound is a copolymer obtainable by using at least one of the
diallyldimethylammonium salts as the cationic monomer (.alpha.) and
copolymerizing the diallyldimethylammonium salt with at least one
anionic monomer (.beta.) selected from fumaric acid, maleic acid,
itaconic acid, and citraconic acid and sulfur dioxide.
[0057] Production of Amphoteric Polymer Compound (P)
[0058] Next, a method for producing the amphoteric polymer compound
(P) used in the present invention will be described. While the
method for producing the amphoteric polymer compound (P) used in
the present invention is not particularly limited, it is preferably
produced according to the method described below.
[0059] First, the cationic monomer (.alpha.), the anionic monomer
(.beta.), and sulfur dioxide are mixed in a polar solvent. Next, in
the polar solvent, the cationic monomer (.alpha.), the anionic
monomer (.beta.), and sulfur dioxide are subjected to a
copolymerization reaction in the presence of a polymerization
catalyst. The molar ratio of cationic monomer (.alpha.)/anionic
monomer (.beta.) is preferably 10/1 to 1/3, more preferably 8/1 to
1/2 and particularly preferably 6/1 to 1/1 as described above. The
molar ratio of cationic monomer (.alpha.)/sulfur dioxide monomer is
preferably 1/1 to 1/0.01, more preferably 1.1/1 to 1/0.025 and
particularly preferably 1.3/1 to 1/0.05 as described above. The
molar ratio of anionic monomer (.beta.)/sulfur dioxide monomer is
preferably 20/1 to 1/20, more preferably 15/1 to 1/15 and
particularly preferably 10/1 to 1/10 as described above. Examples
of the polar solvent can include water, methanol, ethanol, dimethyl
sulfoxide, dimethylformamide and mixed solvents thereof. Among
these, water is preferable from the viewpoint of polymerization
reactivity and safety.
[0060] In the production of the amphoteric polymer compound (P)
used in the present invention, as long as the advantageous effects
of the present invention are not impaired, a fourth monomer that is
a monomer not corresponding to any of the cationic monomer
(.alpha.), the anionic monomer (.beta.) and sulfur dioxide, such as
monoallylamine and acrylamide may be used in a proportion of, for
example 15 mol % or less, preferably 10 mol % or less, and more
preferably 5 mol % or less based on the total monomers.
[0061] While the concentration of the monomer in the reaction
solution during the polymerization of amphoteric polymer compound
(P) varies depending on the species of the monomer, it is usually
10 to 75 mass %, preferably 30 to 70 mass %, and more preferably 50
to 65 mass %. The copolymerization reaction is usually a radical
polymerization reaction performed in the presence of a radical
polymerization catalyst. The kind of the radical polymerization
catalyst is not particularly limited, and preferable examples
thereof include peroxides such as t-butyl hydroperoxide;
persulfates, such as ammonium persulfate, sodium persulfate, and
potassium persulfate and water-soluble azo compounds such as azobis
compounds and diazo compuonds.
[0062] The amount of the radical polymerization catalyst to be
added is usually 0.1 to 20 mol %, and preferably 1.0 to 10 mol %,
based on the total monomers. The polymerization temperature is
usually 0 to 100.degree. C., and preferably 5 to 80.degree. C. The
polymerization time is usually 20 to 150 hours, and preferably 30
to 100 hours. The polymerization atmosphere may be in the air
because polymerizability is not significantly affected.
Alternatively, the polymerization can be performed under an
atmosphere of an inert gas such as nitrogen.
[0063] Amphoteric Polymer Compound (P')
[0064] A second anti-corrosive agent for washing of a metal with an
acid according to the present invention comprises an amphoteric
polymer compound (P') obtainable by copolymerizing at least one
species of the cationic monomers (.alpha.), at least one species of
the anionic monomers (.beta.) and sulfur dioxide. Here, the
cationic monomer (.alpha.), the anionic monomer (.beta.) and sulfur
dioxide are the same as those described above. Moreover, "comprise"
is used with the same intention as that described with respect to
the first anti-corrosive agent for washing of a metal with an acid
of the present invention. The amphoteric polymer compound (P') may
be that corresponding to the amphoteric polymer compound (P).
[0065] Anti-Corrosive Agent For Washing of Metal With Acid
[0066] The anti-corrosive agent for washing of a metal with an acid
according to the present invention may be entirely constituted of
the amphoteric polymer compound (P) or the amphoteric polymer
compound (P'), or may be partially constituted of the amphoteric
polymer compound (P) or the amphoteric polymer compound (P').
Accordingly, after the polymerization is completed, the amphoteric
polymer compound (P) or the amphoteric polymer compound (P') may be
used as the anti-corrosive agent for washing of a metal with an
acid of the present invention by using the solution after
completion of the polymerization as it is. Alternatively, an
organic solvent such as acetone may be added to the solution after
completion of the polymerization to reprecipitate, solidify and use
the compound as the anti-corrosive agent.
[0067] Detergent Solution Composition
[0068] The detergent solution composition of the present invention
contains the anti-corrosive agent for washing of a metal with an
acid of the present invention in an amount of usually 0.1 to 50000
mg, preferably 1 to 10000 mg, and more preferably 1 to 5000 mg
based on 1 L of the acid solution in terms of a solid or pure
compound of amphoteric polymer compound (P) or amphoteric polymer
compound (P'). A necessary anti-corrosion effect can be obtained as
the content is 0.1 mg or more based on 1 L of the acid solution.
The anti-corrosion effect can be improved corresponding to the
amount of the anti-corrosive agent for washing of a metal with an
acid to be added as the content is 50000 mg or less.
[0069] While the acid used for the acid solution is not
particularly limited, inorganic acids such as hydrochloric acid,
sulfuric acid, sulfamic acid and hydrofluoric acid; organic acids
such as formic acid, oxalic acid, citric acid, malic acid,
hydroxyacetic acid and gluconic acid; and chelating agents such as
ethylenediaminetetraacetic acid are preferable.
[0070] The anti-corrosive agent of the present invention may be
added to the acid solution when it is used. Alternatively, it may
be added to the acid solution in advance to prepare the detergent
solution composition of the present invention and then be used
directly or used following the dilution with water. Further, a
surfactant or a solvent may be used in order to improve the mixing
with the detergent solution. The surfactant or solvent used for
this purpose may be mixed with the anti-corrosive agent of the
present invention in advance, or may be added to the detergent
solution composition of the present invention separately.
[0071] The anti-corrosive agent according to the present invention
may be used in combination with another anti-corrosive agent. The
other anti-corrosive agent may be mixed with the anti-corrosive
agent of the present invention in advance, or may be added to the
detergent solution composition of the present invention
separately.
[0072] Specific examples of the other anti-corrosive agent used in
combination include, but not limited to,
1-vinyl-3-ethylimidazolinium bromide, 3-ethylbenzothiazolium
bromide and ethyltriethanolammonium bromide.
[0073] Further, in the detergent solution composition of the
present invention, an acid washing accelerator, such as sulfites,
for improving the acid washing rate may be used in combination.
[0074] Method for Washing of Metal
[0075] The method for washing of metal of the present invention is
characterized in that the detergent solution composition of the
present invention is sprayed to a surface of the metal or the
surface of the metal is immersed in the detergent solution
composition to wash the surface of the metal.
[0076] The detergent solution composition containing the
anti-corrosive agent according to the present invention is sprayed
to the surface of the metal to be washed or a metal piece to be
washed is immersed in the detergent solution composition to wash
the surface of the metal. While the metal to be washed is not
particularly limited, the method is particularly effective when
applied to steel.
EXAMPLES
[0077] Hereinafter, the present invention will be described in
detail with reference to Examples. The scope of the present
invention will not be limited by these Examples in any meaning.
[0078] In Examples, the following abbreviations are used in some
cases:
DADMAC: an abbreviation for diallyldimethylammonium chloride MA: an
abbreviation for maleic acid SO.sub.2: an abbreviation for sulfur
dioxide AMPS: an abbreviation for
2-acrylamide-2-methylpropanesulfonic acid DA.HCl: an abbreviation
for diallylaminehydrochloric acid salt
[0079] In Synthesis Examples, the weight average molecular weight
and polymerization rate of the copolymer were measured by gel
permeation chromatography (GPC) using a Hitachi L-6000 high speed
liquid chromatograph. A Hitachi L-6000 was used as an eluent flow
path pump, and a Shodex RI SE-61 differential refractive index
detector was used as a detector. As a column, an Asahipak aqueous
gel filtration type GS-220HQ (exclusion limit molecular weight of
3,000) and GS-620HQ (exclusion limit molecular weight of 2,000,000)
were doubly connected and used. A sample was adjusted with an
eluent to have a concentration of 0.5 g/100 mL, and 20 .mu.L of the
sample was used. As the eluent, a 0.4 mol/L sodium chloride aqueous
solution was used. The measurement was performed at the column
temperature of 30.degree. C. and the flow rate of 1.0 mL/min.
Polyethylene glycols having the molecular weights of 106, 194, 440,
600, 1470, 4100, 7100, 10300, 12600, 23000, and the like were used
as standard samples, and calibration curves were determined. Based
on the calibration curves, the weight average molecular weight of
the copolymer was determined.
Synthesis Example 1
[0080] Synthesis Example of 10:5:5 ternary copolymer of
diallyldimethylammonium chloride, maleic acid and sulfur
dioxide
[0081] In a 500 mL four-necked separable flask equipped with a
stirrer, a cooling pipe and a thermometer, 248.7 g (1.0 mol) of a
65 mass % of DADMAC aqueous solution, 58.0 g (0.5 mol) of MA and
32.0 g (0.5 mol) of SO.sub.2 were dissolved in 80.8 g of water.
Then, 67.1 g of a 28.5 mass % of ammonium persulfate aqueous
solution (7.6 mass% based on the monomer; 4.2 mol % based on the
total monomers) was added, and polymerization was performed at 18
to 70.degree. C. for 72 hours to synthesize the copolymer specified
in the title and to be used in Example 1. The solution after the
completion of the polymerization was measured by the GPC method to
reveal that the weight-average molecular weight was 23,000 and the
polymerization rate was 100%.
Synthesis Examples 2 to 4
[0082] Synthesis Examples of ternary copolymer of
diallyldimethylammonium chloride, maleic acid and sulfur dioxide
having various copolymerization ratios
[0083] The copolymers specified in the title an to be used in
Examples 2 to 4 were synthesized by the same operation as that in
Synthesis Example 1 except that the copolymerization ratio of
diallyldimethylammonium chloride, maleic acid and sulfur dioxide
was changed as below. In Synthesis Example 2 (copolymerization
ratio of 10:4:1), the weight-average molecular weight was 24,000
and the polymerization rate was 100%. In Synthesis Example 3
(copolymerization ratio of 10:3.5:1.5), the weight-average
molecular weight was 23,000 and the polymerization rate was 100%.
In Synthesis Example 4 (copolymerization ratio of 10:2:3), the
weight-average molecular weight was 23,000 and the polymerization
rate was 100%.
Comparative Synthesis Example 1
[0084] Synthesis Example of 1:1 binary copolymer of
diallyldimethylammonium chloride and maleic acid
[0085] In a 500 mL four-necked separable flask equipped with a
stirrer, a cooling pipe and a thermometer, 116.1 g (1.0 mol) of MA
was dissolved in 248.7 g (1.0 mol) of 65 mass % DADMAC aqueous
solution, and the internal temperature was raised to 50.degree. C.
After the temperature was stabilized, 67.1 g of a 28.5 mass %
ammonium persulfate aqueous solution was added to the obtained
dissolution solution, and polymerization was performed at 50 to
70.degree. C. for 72 hours to synthesize the copolymer specified in
the title and to be used in Comparative Example 1. The solution
after the completion of the polymerization was measured by the GPC
method to reveal that the weight average molecular weight was
11,800 and the polymerization rate was 100%.
Comparative Synthesis Example 2
[0086] Synthesis Example of 2:1 binary copolymer of
diallyldimethylammonium chloride and maleic acid
[0087] The copolymer specified in the title and to be used in
Comparative Example 2 was produced by the same operation as that in
Comparative Synthesis Example 1 except that the copolymerization
ratio of diallyldimethylammonium chloride and maleic acid was
changed. The weight average molecular weight was 24,000, and the
polymerization rate was 100%.
Comparative Synthesis Example 3
[0088] Synthesis Example of 10:5:5 ternary copolymer of
diallyldimethylammonium chloride:
2-acrylamide-2-methylpropanesulfonic acid and sulfur dioxide
[0089] In a 500 mL four-necked separable flask equipped with a
stirrer, a cooling pipe and a thermometer, 248.7 g (1.0 mol) of 65
mass % DADMAC aqueous solution, 103.6 g (0.5 mol) of AMPS and 32.0
g (0.5 mol) of SO.sub.2 were dissolved in 242.3 g of water. Then,
67.1 g of 28.5 mass % ammonium persulfate aqueous solution was
added, and polymerization was performed at 18 to 70.degree. C. for
72 hours to produce the copolymer specified in the title and to be
used in Comparative Example 3. The solution after the completion of
the polymerization was measured by the GPC method to reveal that
the weight-average molecular weight was 11,500 and the
polymerization rate was 95.0%.
Comparative Synthesis Example 4
[0090] Synthesis Example of 1:1 binary copolymer of
diallylaminehydrochloric acid salt and sulfur dioxide
[0091] In a 500 mL four-necked separable flask equipped with a
stirrer, a cooling pipe and a thermometer, 202.5 g (1.0 mol) of 66
mass % DA.HC1 and 64.1 g (1.0 mol) of SO.sub.2 were dissolved in
206.7 g of water. Then, 13.7 g of 28.5 mass % ammonium persulfate
aqueous solution was added, and polymerization was performed at 18
to 60.degree. C. for 24 hours to produce the copolymer specified in
the title and to be used in Comparative Example 4. The solution
after the completion of the polymerization was measured by the GPC
method to reveal that the weight average molecular weight was 5,000
and the polymerization rate was 96.0%.
Comparative Synthesis Example 5
[0092] Synthesis Example of 1:1 binary copolymer of
diallyldimethylammonium chloride and sulfur dioxide
[0093] In a 500 mL four-necked separable flask equipped with a
stirrer, a cooling pipe and a thermometer, 248.7 g (1.0 mol) of 65
mass % DADMAC and 64.1 g (1.0 mol) of SO.sub.2 were dissolved in
210.0 g of water. Then, 16.5 g of 28.5 mass % ammonium persulfate
aqueous solution was added, and polymerization was performed at 18
to 60.degree. C. for 72 hours to produce the copolymer specified in
the title and to be used in Comparative Example 5. The solution
after the completion of the polymerization was measured by the GPC
method to reveal that the weight-average molecular weight was 4,200
and the polymerization rate was 95.0%.
Examples 1 to 4 and Comparative Examples 1 to 6
[0094] Measurement of solubility, amount of corrosion, corrosion
suppression rate, and performance deterioration rate
[0095] With respect to each of the copolymers obtained in Synthesis
Examples and Comparative Synthesis Examples, above, a detergent
solution composition was prepared by the following method and
evaluated.
(Preparation of Detergent Solution Composition)
[0096] To 500 mL of a detergent solution aqueous solution
comprising a 3.5 mass % hydrochloric acid aqueous solution
(hereinafter, referred to an "acid solution"), each of the
copolymers produced in Synthesis Examples and Comparative Synthesis
Examples (that constitutes the anti-corrosive agent according to
the present invention) was added in an amount of 50 mg or1000 mg
(in terms of the solid content) according to Table 1 to obtain a
detergent solution composition.
(Solubility)
[0097] In the preparation of the detergent solution composition,
above, the state of the solution when the anti-corrosive agent was
added to the detergent solution aqueous solution was visually
observed to evaluate the solubility. The state in which turbidity
was recognized was classified as "turbid", and the state of
complete dissolution without turbidity was classified as "not
turbid".
(Amount of Corrosion)
[0098] The detergent solution composition prepared by the method,
above, was heated to 80.degree. C. Then, a hot-rolled steel sheet
(JIS3131) polished with a #180 waterproof polishing paper was
immersed in the detergent solution composition for 10 minutes. From
the surface area of the test piece and measurement results of the
weight of the test piece before and after the immersion, the amount
of corrosion was calculated according to the following expression
(1).
amount of corrosion (mg/cm.sup.2)=[weight of test piece before
immersion (mg)-weight of test piece after immersion (mg)]/surface
area of test piece (cm.sup.2) (1)
(Corrosion Suppression Rate)
[0099] From the result of the amount of corrosion calculated
according to the expression (1), the corrosion suppression rate was
calculated according to the following expression (2).
anti-corrosion rate (%)=[amount of corrosion in Comparative Example
6 (mg/cm.sup.2)-amount of corrosion in each Example or Comparative
Example (mg/cm.sup.2)].times.100/amount of corrosion in Comparative
Example 6 (mg/cm.sup.2) (2)
(Performance Deterioration Rate)
[0100] From the corrosion suppression rate when the amount of the
anti-corrosive agent added was 1000 mg and the corrosion
suppression rate when the amount of the anti-corrosive agent added
was 50 mg, the performance deterioration rate was calculated
according to the following expression (3).
performance reducing rate (%)=100-A (3)
(A=(corrosion suppression rate when the amount of the
anti-corrosive agent added was 1000 mg (%).times.100)/corrosion
suppression rate when the amount of the anti-corrosive agent added
was 50 mg (%))
[0101] The results are shown in Table 1. The result of the test
performed using only the acid solution with no anti-(acid)
corrosive agent added is also shown in Table 1 as "Blank"
(Comparative Example 6).
[0102] With reference to Table 1, it turned out that the
anti-corrosive agent for washing of a metal with an acid according
to the present invention has high solubility in the acid solution.
Additionally, it turned out that the anti-corrosive agent for
washing of a metal with an acid according to the present invention
has a high corrosion suppression rate both in the concentrations of
the added amounts of 50 mg and 1000 mg and furthermore that the
corrosion suppression rate changes little even when the
concentration changes and that the performance deterioration rate
is small.
TABLE-US-00001 TABLE 1 Results of test of anti-corrosion in acid
washing Amount of corrosion Performance Name of sample
Copolymerization Amount corrosion suppression deterioration
(Synthesis Example) ratio added [mg] Solubility [mg/cm.sup.2] rate
[%] rate [%] Example 1 P (DADMAC-MA-SO.sub.2) 10:5:5 50 Not turbid
0.114 91.5 2.52 (Synthesis Example 1) 1000 Not turbid 0.145 89.2 2
P (DADMAC-MA-SO.sub.2) 10:4:1 50 Not turbid 0.157 88.3 2.61
(Synthesis Example 2) 1000 Not turbid 0.188 86.0 3 P
(DADMAC-MA-SO.sub.2) 10:3.5:1.5 50 Not turbid 0.176 86.9 2.65
(Synthesis Example 3) 1000 Not turbid 0.207 84.6 4 P
(DADMAC-MA-SO.sub.2) 10:2:3 50 Not turbid 0.163 87.9 2.62
(Synthesis Example 4) 1000 Not turbid 0.194 85.6 Comparative 1 P
(DADMAC-MA) 1:1 50 Not turbid 0.274 79.6 2.90 Example (Comparative
Synthesis 1000 Not turbid 0.305 77.3 Example 1) 2 P (DADMAC-MA) 2:1
50 Not turbid 0.252 81.3 3.02 (Comparative Synthesis 1000 Not
turbid 0.285 78.8 Example 2) 3 P (DADMAC-AMPS-SO.sub.2) 10:5:5 50
Not turbid 0.203 84.9 4.99 (Comparative Synthesis 1000 Not turbid
0.260 80.7 Example 3) 4 P (DA.cndot.HCl--SO.sub.2) 1:1 50 Not
turbid 0.094 93.0 13.97 (Comparative Synthesis 1000 Turbid 0.269
80.0 Example 4) 5 P (DADMAC-SO.sub.2) 1:1 50 Not turbid 0.141 89.5
25.68 (Comparative Synthesis 1000 Not turbid 0.450 66.5 Example 5)
6 Blank -- -- -- 1.345 -- -- In Table 1, the following
abbreviations are used: P(DADMAC-MA-SO.sub.2):
poly(diallyldimethylammonium chloride/maleic acid/SO.sub.2)
P(DADMAC-MA): poly(diallyldimethylammonium chloride/maleic acid)
P(DADMAC-AMPS-SO.sub.2): poly(diallyldimethylammonium
chloride/2-acrylamide-2-methylpropanesulfonic acid/SO.sub.2)
P(DA.cndot.HCl--SO.sub.2): poly(diallylamine hydrochloric acid
salt/SO.sub.2) P(DADMAC-SO.sub.2): poly(diallyldimethylammonium
chloride/SO.sub.2)
Industrial Applicability
[0103] The anti-corrosive agent for washing of a metal with an acid
according to the present invention and the detergent solution
composition and washing method using the same demonstrate a high
anti-corrosion effect in acid washing of various surfaces of metals
and show little change in the anti-corrosion effect even when the
concentration of the anti-corrosive agent changes. Accordingly, the
present invention is highly valuable and has high applicability in
a variety of industries such as the metal industries.
* * * * *