Note: Descriptions are shown in the official language in which they were submitted.
CA 02591214 2007-06-08
WO 2006/062037 Al
PCT/JP2005/022176
COMPOSITION FOR METAL SURFACE TREATMENT, TREATING LIQUID FOR
SURFACE TREATMENT, METHOD OF SURFACE TREATMENT, AND
SURFACE-TREATED METAL MATERIAL
Technical Field
[0001] The present invention pertains to a composition for surface treatment,
treating
liquid for surface treatment, method of surface treatment, and surface-treated
metal materials
obtained by said treatment method. The composition will allow deposition of a
surface coating
film with excellent corrosion resistance or bare corrosion resistance after
coating the surface of
metal material such as building materials and home electrical appliance
materials.
Background Technology
[0002] The phosphoric acid zinc treatment method or the chromate treatment
method is
commonly used for deposition of a surface coating film with excellent
corrosion resistance on
the surface of metal materials after coating. With the phosphoric acid zinc
treatment method, a
film with excellent corrosion resistance can be deposited on a steel plate or
zinc-plated steel plate
such as a hot rolled steel plate or cold rolled steel plate.
[0003] However, the formation of sludge as a byproduct during the phosphoric
acid zinc
treatment cannot be avoided. With the chromate treatment method, although
sufficient
performance can be ensured after coating, there is a tendency to avoid using
this method from
the standpoint of current environmental regulations because the treatment
liquid contains
harmful hexavalent chromium.
[0004] Therefore, techniques have been developed in recent years to provide
the
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necessary corrosion resistance using a treatment liquid that contains no
harmful components and
in which sludge does not form. Such techniques involve coating the surface of
the base material
with a thin film of a metal such as zirconium. Surface treatment methods of
the kind described
below have been proposed.
[0005] For example, in the method described in Patent Reference 1, a non-
chrome
coating for metal surface treatment that contains a compound having a nitrogen
atom with a lone
electron pair or that contains the aforementioned compound and a zirconium
compound is used.
The purpose of this method is to obtain a surface coating film with excellent
corrosion resistance
and adherence with the use of the aforementioned compositions that contain no
harmful
hexavalent chromium.
[0006] However, the use of this method is limited to metal base materials such
as
aluminum alloys. Moreover, it is difficult to use this method for coating a
material with a
complex structure because a coating drying process is required for the
formation of the surface
coating film.
[0007] In the method described in Patent Reference 2, a surface treatment
agent and a
treatment bath containing selenium, zirconium, phosphoric acid, and fluorine
compounds are
used for the deposition of a surface coating film with excellent tight bonding
and corrosion
resistance after coating by means of a formation reaction.
[0008] The use of this method, as in the case of the method described in
Patent
Reference 1, is limited to aluminum or aluminum alloys, which are metal base
materials already
having excellent corrosion resistance. This method cannot be used for the
deposition of a surface
coating film on the surface of iron-based material or zinc-based material.
[0009] In the method described in Patent Reference 3, a metallic surface
treatment
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=
composition consisting of a metal acetylacetonate and a water-soluble
inorganic titanium
compound or water-soluble inorganic zirconium compound is used for the
deposition of a
surface coating film with excellent corrosion resistance and adherence after
coating. This
method can be used to treat metal materials other than aluminum alloys, such
as magnesium,
magnesium alloys, zinc, and zinc plated alloys.
[0010] However, this method cannot be used for the deposition of a surface
coating film
on the surface of iron-based metal materials such as hot rolled steel plate or
cold rolled steel
plate.
[0011] In addition, a metal surface treatment using a chromium-free coating
type acid
composition has been described in Patent Reference 4. In this metal surface
treatment method,
an aqueous solution of components capable of forming a film with excellent
corrosion resistance
is coated on a metal surface and then a baking/drying process is carried out
for fixing the formed
film without a water washing process. Therefore, no chemical reaction is
involved in the
formation of the film and thus it is possible to use this method for the
deposition of a film on the
surface of metals such as hot rolled steel plate, cold rolled steel plate,
zinc-plated steel plate, and
aluminum alloys.
[0012] However, with this method, the film is formed by coating and drying as
in the
case of the method described in Patent Reference 1 and thus it is difficult to
achieve a uniform
film coating on a material with a complex structure.
[0013] In Patent Reference 5, a metal chemical conversion method using a
treatment
bath containing zirconium ion and/or titanium ion and fluorine ion is
described. This method is
applicable to iron-based metal materials as well as aluminum and zinc.
[0014] However, this method requires using an oxidizing agent for controlling
the iron
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ion concentration in the chemical conversion agent during the conversion
process.
[0015] Therefore, this method cannot be used to carry out a highly workable
surface
treatment capable of depositing a film with excellent corrosion resistance and
adherence on
metal materials such as iron-based metal materials, zinc-based metal
materials, etc., using a
treatment liquid containing none of the environmentally harmful components
used in the
conventional technique.
Patent Reference 1: Japanese Patent Publication No. 2000-204,485
Patent Reference 2: Japanese Patent Publication No. 2[1990]-25,579
Patent Reference 3: Japanese Patent Publication No. 2000-199,077
Patent Reference 4: Japanese Patent Publication No. 5[1993]-195,244
Patent Reference 5: Japanese Patent Publication No. 2004-43913
Description of the Invention
Problems to Be Solved by the Invention
[0016] The purpose of the present invention is to provide a composition for
surface
treatment, treating liquid for surface treatment, method of surface treatment,
and surface-treated
metal materials obtained by said treatment method. Said composition will allow
deposition of a
surface coating film having excellent corrosion resistance or bare corrosion
resistance after
coating on the surface of metal materials, for example, iron-based metal
materials such as hot
rolled steel plate, cold rolled steel plate used in building materials and
home electrical appliance
materials, zinc-based metal materials such as zinc-plated steel plate, etc.
Furthermore, said
surface treatment method uses a treating liquid that contains none of the
environmentally
harmful components used in the conventional technique.
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An Approach to Solving the Problems
[0017] We have carried out extensive studies on methods for solving the
problems
described above and were able to develop a composition for surface treatment,
treating liquid for
surface treatment, method of surface treatment, and surface-treated metal
materials obtained by
said treatment method, unlike those of the conventional technique.
[0018] The aforementioned problems can be solved by the present inventions as
described in sections (1)-(17) given below.
[0019] (1) A composition for the surface treatment of metals that contains
iron and/or
zinc that comprises a component (A), component (B), and component (C) as
described below.
(A) A compound containing at least one element selected from the group
consisting of Ti,
Zr, Hf, and Si.
(B) A compound containing Y and/or a lanthanide element.
(C) Nitric acid and/or a nitric acid compound.
In the aforementioned composition, the ratio of the total mass concentration B
of the
aforementioned Y and/or lanthanide element contained in the aforementioned
component (B) to
the total mass concentration A of the aforementioned elements contained in the
aforementioned
component (A), i.e., K1 = B/A, is in the range of 0.05 and the ratio of the
total mass
concentration C of the nitrogen atoms contained in the aforementioned
component (C) in terms
of the NO3 concentration to the aforementioned total mass concentration A,
i.e., K2 = C/A, is in
the range of 0.01
[0020] (2) A composition for surface treatment as described in the
aforementioned (1)
that contains a component (D) as described below:
(D) At least one fluorine-containing compound.
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[0021] (3) A treatment liquid for the surface treatment of metals containing
iron and/or
zinc that comprises a component (A), component (B), and component (C) as
described below.
(A) A compound containing at least one element selected from the group
consisting of Ti,
Zr, Hf, and Si.
(B) A compound containing Y and/or a lanthanide element.
(C) Nitric acid and/or a nitric acid compound.
In the aforementioned composition, the ratio of the total mass concentration B
of the
aforementioned Y and/or lanthanide element contained in the aforementioned
component (B) to
the total mass concentration A of the aforementioned elements contained in the
aforementioned
component (A), i.e., K1 = B/A, is in the range of 0.05 __K1 the ratio of
the total mass
concentration C of the nitrogen atoms contained in the aforementioned
component (C) in terms
of the NO3 concentration to the aforementioned total mass concentration A,
i.e., K2 = C/A, is in
the range of 0.01 =K2 .200 and the aforementioned total mass concentration A
is in the range
of 10 ppm __10,000 ppm.
[0022] (4) A treatment liquid for surface treatment as described in the
aforementioned (3)
that contains a component (D) as described below:
(D) At least one fluorine-containing compound,
and the free fluorine ion concentration D is in the range of 0.001 ppm .300
ppm.
[0023] (5) A treatment liquid for surface treatment as described in the
aforementioned (3)
or (4) having a pH value of no more than 6Ø
[0024] (6) A treatment liquid for surface treatment as described in any one of
the
aforementioned (3)-(5) that contains at least one compound selected from the
group consisting of
HC1, H2504, HC103, HBr03, HNO2, HMn04, HVO3, H202, H2W04, H2Mo04 and their
salts in a
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concentration in the range of 10-20,000 ppm.
[0025] (7) A treatment liquid for surface treatment as described in any one of
the
aforementioned (3)-(6) that contains at least one compound selected from the
group consisting of
ethylenediamine tetraacetic acid, gluconic acid, heptogluconic acid, glycolic
acid, citric acid,
succinic acid, fumaric acid, aspartic acid, tartaric acid, malonic acid, malic
acid, salicylic acid,
and their salts in a concentration in the range of 1-10,000 ppm.
[0026] (8) A treatment liquid for surface treatment as described in any one of
the
aforementioned (3)-(7) that contains a water-soluble polymer compound and/or a
water-
dispersible polymer compound.
[0027] (9) A treatment liquid for surface treatment as described in any one of
the
aforementioned (3)-(8) that contains at least one surfactant selected from a
group consisting of
nonionic surfactants, anionic surfactants, and cationic surfactants.
[0028] (10) A surface treatment method for metals containing iron and/or zinc
that
includes a treatment liquid contact process in which a metal material
containing iron and/or zinc
is brought into contact with the treatment liquid for surface treatment
described in any one of the
aforementioned (3)-(8).
[0029] (11) A surface treatment method for metals containing iron and/or zinc
that
includes a treatment liquid contact process in which a metal material
containing iron and/or zinc
is brought into contact with the treatment liquid for surface treatment as
described in the
aforementioned (9) to simultaneously carry out a degreasing treatment and a
film formation
treatment on the aforementioned metal material.
[0030] (12) A surface treatment method as described in the aforementioned (10)
or (11)
in which the aforementioned metal material that contains iron and/or zinc is a
metal material that
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,
-
has been cleansed by a degreasing treatment.
[0031] (13) A surface treatment method as described in any one of the
aforementioned
(10)-(12) in which the aforementioned treatment liquid contact process
involves an electrolytic
treatment using the aforementioned metal material that contains iron and/or
zinc as a cathode.
[0032] (14) A surface treatment method as described in any one of the
aforementioned
(10)-(13) that includes a process in which the aforementioned metal material
that contains iron
and/or zinc is brought into contact with an aqueous solution containing at
least one of the
elements selected from a group consisting of cobalt, nickel, tin, copper,
titanium, and zirconium
after the aforementioned treatment liquid contact process.
[0033] (15) A surface treatment method as described in any one of the
aforementioned
(10)-(13) that includes a process in which the aforementioned metal material
that contains iron
and/or zinc is brought into contact with an aqueous solution containing a
water-soluble polymer
compound or a water-dispersible polymer compound after the aforementioned
treatment liquid
contact process. More specifically, in one embodiment, the method is a surface
treatment
method for iron-based and/or zinc-based metal materials that includes a
treatment liquid contact
process in which the metal material is brought into contact with a treatment
liquid for surface
treatment that comprises a component (A), component (B), component (C) and
component (D)
as described below:
(A) a compound containing at least one element selected from a group
consisting of Ti , Zr, Hf, and Si with a total mass concentration A of the
aforementioned element in the range of 10 ppm < A < 10,000 ppm;
(B) a compound containing at least one element selected from the group
consisting of Y, La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu;
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(C) nitric acid and/or a nitric acid compound;
(D) at least one fluorine-containing compound;
wherein the ratio of the total mass concentration B of the at least one
element of component (B)
to the total mass concentration A of the aforementioned elements contained in
the
aforementioned component (A), i.e., K1 = B/A, is in the range of 0.05 _.K1
and the ratio of
the total mass concentration C of the nitrogen atoms contained in the
aforementioned component
(C) in terms of the NO3 concentration to the aforementioned total mass
concentration A, i.e., K2
= C/A, is in the range of 0.01 00;
wherein the free fluorine ion concentration D is in the
range of 0.001 ppm :51) 00 ppm.
[0034] (16) An iron-containing metal material having a surface coating film
layer that is
formed on the surface of the iron-containing metal material by the surface
treatment method
described in any one of the aforementioned (10)-(15), that contains the
aforementioned elements
of the aforementioned component (A) and that has an adhesion quantity in terms
of the
aforementioned elements of greater than 20 mg/cm2.
[0035] (17) A zinc-containing metal material having a surface treatment film
layer that is
formed on the surface of the iron-containing metal material by the surface
treatment method
described in any one of the aforementioned (10)-(15), that contains the
aforementioned elements
of the aforementioned component (A) and that has an adhesion quantity in terms
of the
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aforementioned elements of greater than 15 mg/cm2.
Effects of the Invention
[0036] A composition for surface treatment of a metal, treating liquid for
surface
treatment, method of surface treatment, and surface-treated metal materials
obtained by said
treatment method of the present invention are epoch-making techniques capable
of depositing a
surface coating film with excellent corrosion resistance after coating on the
surface of the metal
material using a treatment bath that contains none of the environmentally
harmful components
used in the conventional technique.
Best Embodiment for Implementation of the Invention
[0037] A composition for surface treatment of a metal of the present invention
(also to
be called simply "the composition of the present invention" in the following),
a treatment liquid
for metal surface treatment of the present invention (also to be called simply
"the treatment
method of the present invention" in the following), and a metal material
containing iron and/or
zinc of the present invention (also to be called simply "the metal material of
the present
invention" in the following) will now be described in more detail. The
composition and the
treatment liquid of the present invention will be explained first.
[0038] The composition of the present invention is diluted with water or
dissolved in
water at the time of its use to form the treatment liquid of the present
invention.
The materials to be surface-treated with the treatment liquid of the present
invention are
iron-based metal materials or zinc-based metal materials.
There are no particular limitations with regard to the kind of iron-based
metal materials
that can be used as long as they contain iron. Suitable materials would
include, for example,
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steel plate such as cold rolled steel plate, hot rolled steel plate, etc.,
cast iron, and sintered
materials.
There are no particular limitations with regard to the kind of zinc-based
metal materials
that can be used as long as they contain zinc. Suitable materials would
include, for example,
zinc die-cast and zinc-containing plated materials. The zinc-containing plated
materials consist
of zinc or alloys of zinc and at least one other element selected from among,
for example, nickel,
iron, aluminum, manganese, chromium, magnesium, cobalt, lead, and antimony,
and unavoidable
impurities. There are no particular limitations with regard to the plating
methods that can be
used. Suitable methods would include, for example, electroplating methods,
fusion plating
methods, vapor deposition plating methods, etc.
[0039] The present invention pertains to surface treatment of the surface of
metal
materials. The metal materials can be surface-treated individually or
combinations of two or
more of them can be treated simultaneously. When two or more metal materials
are to be treated
simultaneously and when at least one of the metal materials is an iron- or
zinc-based metal
material, the other metal material can be aluminum, magnesium, nickel, or
their alloys.
Moreover, the different metals may not be in contact with each other or they
can be in contact
with each other or joined together by a welding, adhesion, or riveting method.
The functions of the present invention will now be described in detail.
[0040] A composition of the present invention contains the component (A),
component
(B), and component (C) as described below.
Component A is a compound containing at least one element selected from the
group
consisting of Ti, Zr, Hf, and Si. Suitable compounds include, for example,
TiC14, Ti(SO4)2,
Ti0504, Ti(NO3)4, TiO(NO3)2, Ti(OH)4, Ti020C204, H2TiF6, salts of H2TiF6, TiO,
Ti02, Ti203,
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TiF4, ZIC14, ZTOC12, Zr(OH)2C12, Zr(OH)3C1, Zr(SO4)2, ZrOSO4, Zr(NO3)4,
ZrO(NO3)2, Zr(OH)4,
H2ZrF6, salts of H2ZrF6, H2(Zr(CO3)2(OH)2, salts of 112(Zr(CO3)2(OH)2,
H2Zr(OH)2(SO4)2, salts
of H2Zr(OH)2(SO4)2, Zr02, ZrOBr2, ZrE4, HfC14, Hf(SO4)2, H2HfF6, salts of
H2HfF6, Hf02, HfF4,
H2SiF6, salts of H2SiF6 and A1203(Si02)3. Two or more of these compounds may
also be used
concomitantly.
[0041] Component (B) is a compound containing Y and/or a lanthanide element;
i.e., a
compound containing at least one element selected from the group consisting of
Y, La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Suitable compounds
include, for
example, oxides, sulfates, nitrates, and chlorides of these elements. More
specifically, for
example, they include yttrium chloride, lanthanide chloride, cerium chloride,
praseodymium
chloride, neodymium chloride, promethium chloride, samarium chloride, europium
chloride,
gadolinium chloride, terbium chloride, dysprosium chloride, holmium chloride,
erbium chloride,
thulium chloride, ytterbium chloride, lutetium chloride, yttrium sulfate,
lanthanide sulfate,
cerium sulfate, praseodymium sulfate, neodymium sulfate, promethium sulfate,
samarium sulfate,
europium sulfate, gadolinium sulfate, terbium sulfate, dysprosium sulfate,
holmium sulfate,
erbium sulfate, thulium sulfate, ytterbium sulfate, lutetium sulfate, yttrium
nitrate, lanthanide
nitrate, cerium nitrate, praseodymium nitrate, neodymium nitrate, promethium
nitrate, samarium
nitrate, europium nitrate, gadolinium nitrate, terbium nitrate, dysprosium
nitrate, holmium nitrate,
erbium nitrate, thulium nitrate, ytterbium nitrate, lutetium nitrate, yttrium
oxide, lanthanide oxide,
cerium oxide, praseodymium oxide, neodymium oxide, promethium oxide, samarium
oxide,
europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium
oxide, erbium
oxide, thulium oxide, ytterbium oxide, and lutetium oxide. Two or more of
these compounds
may also be used concomitantly.
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[0042] Component (C) is nitric acid and/or a nitric acid compound. Suitable
compounds
include, for example, nitric acid, metal nitrates, etc. Metal nitrates would
include, for example,
ferric nitrate, manganese nitrate, nickel nitrate, cobalt nitrate, silver
nitrate, sodium nitrate,
potassium nitrate, magnesium nitrate, and calcium nitrate. Two or more of
these compounds
may also be used concomitantly.
[00431 A composition of the present invention is diluted with water or
dissolved in water
at the time of its use for the surface treatment of a metal. Namely, the
treatment liquid for metal
surface treatment is prepared and used. In preparing the treatment liquid for
metal surface
treatment, water is added to the composition for metal surface treatment to
bring the total mass
concentration of the aforementioned elements (Ti, Zr, Hf, and Si) of the
aforementioned
component (A) within the range of 10 ppm to 10,000 ppm.
[00441 The term "the total mass concentration A of the aforementioned elements
contained in the aforementioned component (A)" indicates "the concentration of
the
aforementioned elements contained in the aforementioned component (A)
contained in the
composition (in some cases, the treatment liquid) of the present invention".
The same is true for the terms "the total mass concentration B" and "the total
mass
concentration C".
[0045] In the composition for surface treatment and the treatment liquid for
surface
treatment of the present invention, the ratio of the total mass concentration
B of the
aforementioned Y and/or lanthanide element contained in the aforementioned
component (B) to
the total mass concentration A of the aforementioned elements contained in the
aforementioned
component (A), i.e., K1 = B/A, is in the range of 0.05 =K1 __50 and the ratio
of the total mass
concentration C of the nitrogen atoms contained in the aforementioned
component (C) in terms
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of the NO3 concentration to the aforementioned total mass concentration A,
i.e., K2 = C/A, is in
the range of 0.01 1(2
[0046] Here, component A is a substance having excellent anti-acid and anti-
alkali
properties and is the main component of the surface coating film of the
present invention.
Component (B) can promote the film deposition of component (A). Moreover,
component (B) may be contained in the surface coating film so that the
corrosion resistance and
bare corrosion resistance of the film after coating can be expected to further
improve.
Component (C) in the treatment liquid for surface treatment serves to maintain
the
stability of the treatment liquid by increasing the solubility of component
(A) and component (B).
Furthermore, component (C) can also assist the film deposition of component
(A), though not as
effectively as component (B).
100471 When the aforementioned K1 = B/A is too small, component (B) can not be
expected to promote the film deposition of component (A) because of the
reduced proportion of
component (B). Consequently, the amount of film adhesion of component (A) will
decrease
compared to that obtained when the total mass concentration ratio of component
(A) to
component (B), i.e., Kl, is within the range of 0.05 ._1(1 and
the corrosion resistance of the
treated metal material may decrease.
When the aforementioned K1 is too large, the reaction initiation point itself
of
component (A) on the surface of the treated metal material may be lowered and
the amount of
film adhesion of component (A), that is the main component of the film and the
component that
provides the corrosion resistance to the film, will decrease even though the
film deposition
promoting effect of component (B) is present. Therefore, excellent corrosion
resistance cannot
be obtained and the adherence may also be adversely affected in some cases.
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[0048] When the aforementioned K2 = C/A is too small, suitable corrosion
resistance of
the treated metal material cannot be obtained and the treatment liquid
stability of the treatment
liquid for surface treatment may be adversely affected. Consequently,
continuous operation may
be hindered. Furthermore, because of the small proportion of component (C) in
the treatment
liquid, the assisting effect of component (C) on the film deposition of
component (A) cannot be
expected.
When K2 = C/A is in the range of 0.01 _.1(2 200, it will be sufficient to
maintain the
stability of the treatment liquid of the present invention. Larger K2 values
will not improve the
corrosion resistance and thus are economically disadvantageous.
[0049] The aforementioned total mass concentration A of the aforementioned
component
(A) used in the treatment liquid of the present invention is preferably
adjusted to be in the range
of 10 ppm to 10,000 ppm, and more preferably in the range of 50 ppm to 5,000
ppm. When the
aforementioned total mass concentration A is too small, it will become
difficult to obtain an
amount of adhesion sufficient for acquiring the desired corrosion resistance
within a practical
treatment time due to the low concentration of the film main component, even
though the
aforementioned K1 and the aforementioned K2 are within the specified ranges.
When the
aforementioned total mass concentration A is too large, although a sufficient
amount of adhesion
can be obtained, the corrosion resistance cannot be improved further and thus
an excessively
high total mass concentration A is not economically desirable.
[0050] It is desirable that the composition and treatment liquid of the
present invention
additionally contain at least one fluorine-containing compound as component
(D). Suitable
compounds include, for example, hydrofluoric acid, H2TiF6, salts of H2TiF6,
TiEt, H2ZrF6, salts
of H2ZrF6, ZrFa, 1121IfF6, salts of H2HfF6, HfF4, H2SiF6, HBF4, salts of HBF4,
NaHF2, KHF2,
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NH4HF2, NaF, KF, and NH4H. Two or more of these fluorine-containing compounds
may also
be used concomitantly.
[0051] When component (D) is to be added to the treatment liquid of the
present
invention, the concentration of at least one of the fluorine-containing
compounds of component
(D) is preferably adjusted so that the free fluorine ion concentration D will
be in the range of
0.001 ppm to 300 ppm, and more preferably in the range of 0.1 ppm to 100 ppm.
Here, the term
"free fluorine ion concentration D" means the fluorine ion concentration
determined with the use
of a commercially available ion electrode. When the free fluorine ion
concentration D is too
high, the etching reaction on the raw material surface by HF will be too
excessive and the
amount of film deposition sufficient to achieve corrosion resistance of the
surface of the treated
metal material will tend to become difficult to obtain. The corrosion
resistance of the surface of
the treated metal material can be achieved even when the free fluorine ion
concentration D
produced by the fluorine-containing compound of component (D) is too small,
but the stability of
the treatment liquid for surface treatment may be adversely affected and
continuous operation
may be hindered.
[0052] Film deposition by the treatment liquid of the present invention is
preferably
induced by the formation reaction accompanying the etching of the metal base
material.
Therefore, the treatment is preferably carried out in a pH range in which an
etching reaction will
ordinarily occur, i.e., a pH value below 6.0, preferably below 5.0, and more
preferably below 4Ø
[0053] There are no particular limitations with regard to the kind of reagent
used for
adjusting the pH of the treatment liquid of the present invention when needed.
For example,
acids such as hydrochloric acid, sulfuric acid, boric acid, and organic acids,
alkalis such as
lithium hydroxide, potassium hydroxide, sodium hydroxide, calcium hydroxide,
magnesium
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hydroxide, barium hydroxide, alkali metal salts, ammonia, ammonium salts, and
amines may be
used.
[0054] A treatment liquid of the present invention may be contaminated by the
metals
contained in the base material which are eluted out by the etching reaction of
the base material,
or by the metals or compounds contained in the tap water and industrial water
because
component (B) can promote the film deposition of component (A) and the film
deposition of
component (A) will not be affected by other metal elements.
[0055] An anion component is preferably added to the treatment liquid of the
present
invention to further promote the film-formation reaction. Suitable anion
components that may be
added to the treatment liquid for surface treatment of the present invention
include, for example,
HC1, H2504, HC103, HBr03, HNO2, HMn04, HVO3, H202, H2W04, H2M004, etc. There
are no
particular limitations with regard to the concentration of the anion component
added; a
concentration in the range of about 10 ppm to 20,000 ppm is sufficient for
providing the desired
effect.
[0056] When the treatment load of the metal material to be treated is high for
the
treatment liquid of the present invention, a chelating agent capable of
chelating metal ions
dissolved out by the etching reaction is preferably added. Suitable chelating
agents that can be
used in the treatment liquid of the present invention include, for example,
ethylenediamine
tetraacetic acid (EDTA), gluconic acid, heptogluconic acid, glycolic acid,
citric acid, succinic
acid, fumaric acid, aspartic acid, tartaric acid, malonic acid, malic acid,
salicylic acid, and their
salts. There are no particular limitations with regard to the content of these
chelating agents. For
example, a concentration in the range of about 1 ppm to 10,000 ppm is
sufficient for providing
the desired effect.
16
CA 02591214 2007-06-08
[0057] A water-soluble polymer compound and/or a water-dispersible polymer
compound having an ionic reactive group in their molecule are preferably added
to the treatment
liquid of the present invention. Suitable compounds include, for example,
copolymers of
polyvinyl alcohol, poly(meth)acrylic acid or acrylic acid, and methacrylic
acid, copolymers of
ethylene and acryl-type monomers such as (meth)acrylic acid, (meth)acrylate,
etc., copolymers
of ethylene and vinyl acetate, polyurethane, amino modified phenol resins,
polyester resins,
epoxy resins, polyamide amines, polyamines, polyamine derivatives, polyallyl
amines, polyallyl
amine derivatives, polyamide amine derivatives, polyvinyl amine, polyvinyl
amine derivatives,
tannin, tannic acid and its salts, and phytic acid. There are no particular
limitations with regard
to the concentration of the aforementioned compounds added, but a
concentration in the range of
1 ppm to 10,000 ppm is preferable. This addition quantity should give a
sufficient effect.
[0058] At least one surfactant selected from a group consisting of nonionic
surfactants,
anionic surfactants, and cationic surfactants is preferably added to the
treatment liquid of the
present invention. When a treatment liquid for surface treatment of this kind
is used for the
surface treatment of a metal base material, as will be mentioned later, a good
film can be formed
without a preliminary degreasing treatment or cleansing treatment of the metal
material to be
treated. Namely, the treatment liquid for surface treatment of the present
invention can be used
as a degreasing surface treatment agent as well as a formation surface
treatment agent.
[0059] The treatment method of the present invention is a surface treatment
method for
metals containing iron and/or zinc that includes a treatment liquid contact
process in which the
metal material containing iron and/or zinc is brought into contact with the
treatment liquid of the
present invention.
[0060] The only requirement of the surface treatment method of the present
invention is
17
CA 02591214 2007-06-08
to bring the aforementioned metal material containing iron and/or zinc into
contact with the
aforementioned treatment liquid of the present invention. In this way a film
made of oxides
and/or hydroxides of the aforementioned elements of the aforementioned
component (A) will be
deposited on the surface of the metal base material and a surface coating film
layer with
excellent adherence and corrosion resistance can thus be formed.
Any method such as a spray treatment, immersion treatment, or cast liquid
treatment
[unconfirmed -- Tr. Ed.] can be used for the contact treatment mentioned
above; the contact
method used will not affect the performance of the film formed.
It is chemically difficult to obtain the hydroxide of metals contained in the
film of the
aforementioned component (A) in the form of a pure hydroxide. In general,
therefore, oxides of
the aforementioned metals with attached water of hydration are also included
in this group of
oxides. Therefore, the aforementioned hydroxides of metal will eventually
become oxides by
heating. As for the structure of the surface coating film of the present
invention, it is believed
that the film is present in the state of a mixture of oxides and hydroxides
when the film is dried at
normal temperature or a low temperature after the surface treatment, whereas
the film is present
in a state in which oxides only or oxides as the majority component are
present when the film is
dried at a high temperature after the surface treatment.
[0061] The aforementioned metal material containing iron and/or zinc is
preferably
subjected to a cleansing process, such as a degreasing treatment. There are no
particular
limitations with regard to the method used for degreasing, i.e., any
conventional method can be
used.
As mentioned before, when the treatment liquid of the present invention
contains the
aforementioned surfactant, a good film can be formed even without pre-
cleansing of the
18
CA 02591214 2007-06-08
aforementioned metal material containing iron and/or zinc by a degreasing
treatment. Namely,
in this case, the degreasing treatment and the film-forming treatment of the
aforementioned metal
material containing iron and/or zinc are carried out at the same time.
[0062] There are no particular limitations with regard to the condition of use
of the
treatment liquid of the present invention.
The reactivity of the treatment liquid of the present invention can be
controlled freely by
changing the ratio of the aforementioned total mass concentration B to the
aforementioned total
mass concentration A, i.e., K1 = B/A, and the ratio of the aforementioned
total mass
concentration C to the aforementioned total mass concentration A, i.e., K2 =
C/A.
Furthermore, even when at least one of the aforementioned component (D)
fluorine-
containing compounds is used, the reactivity can still be controlled by
changing the free fluorine
ion concentration D. The treatment temperature and treatment time can be
altered freely in
accordance with the reactivity of the treatment bath.
[0063] In the treatment method of the present invention, an electrolytic
treatment with
the aforementioned metal material containing iron and/or zinc as the cathode
can be carried out
while the metal material is in the state of contact with the treatment liquid
of the present
invention.
In this case, a hydrogen reducing reaction will occur at the interface of the
aforementioned metal material containing iron and/or zinc serving as the
cathode and the pH will
rise. With a rising pH, the stability of the compound containing the elements
of component (A)
at the cathode interface will decrease and the surface treatment film will be
deposited as an oxide
or as a water-containing hydroxide.
[0064] After the aforementioned metal material containing iron and/or zinc has
made
19
CA 02591214 2007-06-08
contact with the treatment liquid of the present invention or has been
subjected to an electrolytic
treatment following such contact, it may then be brought into contact with an
acidic aqueous
solution containing at least one element selected from a group consisting of
cobalt, nickel, tin,
copper, titanium, and zirconium or with a treatment solution containing at
least one water-
soluble polymer compound and/or water-dispersible polymer compound. In this
way, the effect
of the present invention can be further enhanced.
[0065] A surface coating film obtained by the present invention is a thin film
with
excellent coating performance. When the surface condition of the metal
material to be treated
shows the presence of an abnormality, the surface treatment film layer may end
up with a very
small defective portion. Therefore, the metal material is brought into contact
with the acidic
aqueous solution containing at least one element selected from a group
consisting of cobalt,
nickel, tin, copper, titanium, and zirconium or with a treatment solution
containing at least one
water-soluble polymer compound and/or water-dispersible polymer compound. In
this way, any
defective portion can be covered and the corrosion resistance can be further
improved.
[0066] There are no particular limitations with regard to the source of supply
of the
aforementioned at least one element selected from a group consisting of
cobalt, nickel, tin,
copper, titanium, and zirconium. Readily available oxides, hydroxides,
fluorides, complex
fluorides, chlorides, nitrates, oxynitrates, sulfates, oxysulfates,
carbonates, oxycarbonates,
phosphates, oxyphosphates, oxalates, oxyoxalates, and organometal compounds of
the
aforementioned metal elements can be used. The acidic aqueous solution
containing the
aforementioned metal elements preferably has a pH value in the range of 2-6.
Acids such as
phosphoric acid, nitric acid, sulfuric acid, hydrofluoric acid, hydrochloric
acid, and organic acids,
and alkalis such as sodium hydroxide, potassium hydroxide, lithium hydroxide,
alkali metal salts,
CA 02591214 2007-06-08
ammonia, ammonium salts, and amines can be used for pH adjustment.
[0067] The aforementioned at least one polymer compound selected from among
water-
soluble polymer compounds and water-dispersible polymer compounds can be, for
example, a
copolymer of polyvinyl alcohol, poly(meth)acrylic acid or acrylic acid, and
methacrylic acid,
copolymers of ethylene and acryl-type monomers such as (meth)acrylic acid,
(meth)acrylate, etc.,
copolymers of ethylene and vinyl acetate, polyurethane, amino modified phenol
resins, polyester
resins, epoxy resins, polyamide amines, polyamines, polyamine derivatives,
polyallyl amines,
polyallyl amine derivatives, polyamide amine derivatives, polyvinyl amine,
polyvinyl amine
derivatives, tannin, tannic acid and its salts, and phytic acid.
[0068] As was described in detail above, with the present invention, the
corrosion
resistance of a metal material can be improved markedly by forming a film
layer made of the
oxides and/or hydroxides of the aforementioned component (A) or a film layer
made of a
mixture of film layers consisting of the film layer of the aforementioned
component (A) and a
film layer made of the oxides and/or hydroxides of the metal elements of the
aforementioned
component (B). Here, any films made of the oxides and/or hydroxides of the
aforementioned
component (A) are acid and alkali resistant and are chemically stable.
[0069] Here, in the actual coated film corrosion environment of a metal, the
pH will
decrease at the anode portion where the elution of metals takes place and the
pH will increase at
the cathode portion where a reduction reaction occurs. Therefore, a surface
coating film with
poor acid and alkali resistance will be dissolved in a corrosive environment
and lose its
effectiveness. A film made of the oxides and/or hydroxides of the
aforementioned component
(A) used in the present invention is resistant to both acids and alkalis. In
addition, with the
present invention, a thin and uniform surface coating film can be formed on
the surface of the
21
CA 02591214 2007-06-08
metal to be treated and thus the superior effect of the present invention can
be maintained even in
a corrosive environment.
[0070] Since the oxides and hydroxides of the metal elements contained in the
film can
form a network structure through metals and oxygen, the formed film is an
excellent barrier film.
The corrosion of a metal material will vary depending on the environment in
which the metal
material is used. In general, however, corrosion will occur under the
condition where water and
oxygen are present and thus is usually of the oxygen requiring type.
Therefore, the corrosion
speed will be increased in the presence of components such as chlorides, etc.
Since the film
layer of the present invention has a barrier effect on water, oxygen, and
corrosion-promoting
components, it offers an excellent anti-corrosion property.
[0071] In addition to the aforementioned component (A) and the aforementioned
component (B), the composition and the treatment liquid of the present
invention may also
contain the aforementioned component (C), the proportions of of which are set
to be within
specified ranges. Therefore, at the time of deposition of the surface coating
film, a formation
reaction will also occur. The accompanying formation reaction can sharply
increase the
adherence property of the film.
[0072] Here, in order to utilize the aforementioned barrier effect to increase
the
corrosion resistance of iron-based metal materials such as cold rolled steel
plate, hot rolled steel
plate, cast iron, sintered materials, etc., the adhering amount of the surface
coating film in terms
of component (A) is preferably greater than 20 mg/m2, more preferably greater
than 30 mg/m2,
and especially greater than 40 mg/m2.
[0073] Moreover, in order to increase the corrosion resistance of zinc-based
metal
materials such as zinc or zinc plated steel plate, zinc electroplated steel
plate, etc., the adhering
22
CA 02591214 2007-06-08
=
amount of the surface coating film in terms of component (A) is preferably
greater than 15
mg/m2, and more preferably greater than 20 mg/m2.
When the adhering amount is too small, the aforementioned barrier effect will
not be
sufficient and it will be difficult to obtain excellent corrosion resistance.
[0074] There are no particular limitations with regard to the upper limit of
the adhering
amount on the iron-based metal material or zinc-based metal material. However,
when the
adhesion amount is too large, cracks will readily from in the surface coating
film and the process
of trying to form a uniform film will become difficult. Therefore, the
adhering amount in terms
of component (A) for both iron-based materials and zinc-based materials is
preferably no more
than 1 g/m2, and especially no more than 800 mg/m2.
ACTUAL EXAMPLES
[0075] The effect of the surface treatment liquid and the surface treatment
method of the
present invention will now be explained in detail with the use of actual
examples and comparison
examples. The material to be treated, the degreasing agent, and the coating
material used were
selected arbitrarily from among commercially available products and should not
restrict in any
way the actual use of the surface treatment liquid and the surface treatment
method.
[0076] Plates Used for the Study
The code designations and description of the plates used in the actual
examples and
comparison examples are given below.
= SPC (cold rolled steel plate; JIS-G-3141)
= EG (zinc electroplated steel plate; plating quantity 20 g/m2)
[0077] Treatment Process
The surface treatment in Actual Examples 1-5 and Comparison Examples 1-3 was
carried
23
CA 02591214 2007-06-08
out in accordance with the following treatment process:
Alkaline degreasing water washing ¨> film formation treatment --0 water
washing ¨>
deionized water washing drying.
100781 In Actual Example 6, the surface treatment was carried out in
accordance with
the following treatment process:
Alkaline degreasing ¨> water washing ---> film formation treatment --> water
washing
post treatment ¨> deionized water washing --> drying.
[0079] In Actual Example 7, the surface treatment was carried out in
accordance with
the following treatment process:.
Alkaline degreasing ¨> water washing --> electroformation treatment ¨> water
washing
---> deionized water washing ¨> drying.
100801 In Comparison Example 4, the surface treatment was carried out in
accordance
with the following treatment process:
Alkaline degreasing ¨> water washing -4. surface preparation ¨> water washing
¨>
deionized water washing ¨> drying.
[0081] For the alkaline degreasing treatment employed in both the actual
examples and
comparison examples, Fine Cleaner L4460A (registered trade name, manufactured
by Nihon
Parkerizing Co., Ltd.) and Fine Cleaner L4460B (registered trade name,
manufactured by the
Nihon Parkerizing Co., Ltd.) diluted with tap water to 2% and 1.4%,
respectively, were sprayed
on the plate to be treated at 40 C for 120 seconds.
100821 For the water washing and deionized water washing treatments in both
the actual
examples and comparison examples, water and deionized water, respectively,
were sprayed on
the plate to be treated at room temperature for 30 seconds.
24
CA 02591214 2007-06-08
The plate was then dried by allowing it to stand in a room at room
temperature.
[0083] Actual Example 1
An aqueous zirconium sulfate solution, lanthanide sulfate, and nitric acid
were used to
prepare a composition for surface treatment with a total mass concentration
ratio K1 = B/A = 0.1
and a total mass concentration ratio K2 = C/A = 0.01. The aforementioned
composition for
surface treatment was diluted with deionized water to adjust the mass
concentration of the
zirconium element to 8,000 ppm. Sodium hydroxide was then used to obtain a
surface treatment
liquid with a pH value of 3.2. A test plate that had been degreased and water-
washed was
immersed in the aforementioned surface treatment liquid at 50 C for 180
seconds for surface
treatment.
[0084] Actual Example 2
An aqueous hexafluoro zirconium solution, samarium nitrate, and nitric acid
were used to
prepare a composition for surface treatment with a total mass concentration
ratio K1 = B/A = 2.0
and a total mass concentration ratio K2 = C/A = 50. The aforementioned
composition for
surface treatment was diluted with deionized water to adjust the mass
concentration of the
zirconium element to 100 ppm. Hydrofluoric acid and ammonia were then used to
obtain a
surface treatment treatment liquid with a free fluorine concentration of 25
ppm (fluorine ion
meter: IM-55G, manufactured by Toa Denpa Kogyo Co., Ltd.) and a pH value of
3.6. A test
plate that had been degreased and water-washed was immersed in the
aforementioned surface
treatment liquid at 45 C for 150 seconds for surface treatment.
[0085] Actual Example 3
An aqueous zirconium nitrate solution, hafnium oxide, gadolinium oxide, and
potassium
nitrate were used to prepare a composition for surface treatment with a total
mass concentration
CA 02591214 2007-06-08
ratio K1 = B/A = 5.0 and a total mass concentration ratio K2 = C/A = 20. The
aforementioned
composition for surface treatment was diluted with deionized water to adjust
the mass
concentration of the zirconium element and the mass concentration of hafnium
element to a
combined mass concentration of 50 ppm. 100 ppm of succinic acid was added to
the liquid thus
obtained and then potassium fluoride and lithium hydroxide were used to obtain
a treatment
liquid for surface treatment with a free fluorine concentration of 20 ppm
(fluorine ion meter:
IM-55G, manufactured by Toa Denpa Kogyo Co., Ltd.) and a pH value of 4Ø A
test plate that
had been degreased and water-washed was immersed in the aforementioned surface
treatment
liquid at 60 C for 120 seconds for surface treatment.
[0086] Actual Example 4
An aqueous zirconium nitrate solution, an aqueous lanthanum chloride solution,
erbium
oxide, sodium nitrate, and nitric acid-soda were used to prepare a composition
for surface
treatment with a total mass concentration ratio K1 = B/A = 35 and a total mass
concentration
ratio K2 = C/A = 100. The aforementioned composition for surface treatment was
diluted with
deionized water to adjust the mass concentration of the zirconium element to
20 ppm.
Hydrofluoric acid and calcium hydroxide were then used to obtain a treatment
liquid for surface
treatment with a free fluorine concentration of 15 ppm (fluorine ion meter: IM-
55G,
manufactured by Toa Denpa Kogyo Co., Ltd.) and a pH value of 3Ø A test plate
that had been
degreased and water-washed was sprayed with the aforementioned surface
treatment liquid at
55 C for 120 seconds for surface treatment.
[0087] Actual Example 5
An aqueous titanium nitrate solution, an aqueous hexafluoro silicate solution,
praseodymium oxide, and potassium nitrate were used to prepare a composition
for surface
26
CA 02591214 2007-06-08
treatment with a total mass concentration ratio K1 = B/A = 0.4 and a total
mass concentration
ratio K2 = C/A = 8Ø The aforementioned composition for surface treatment was
diluted with
deionized water to adjust the mass concentration of the zirconium element and
the mass
concentration of the silicon element to a combined mass concentration of 2,500
ppm.
Ammonium fluoride and ammonia were then used to obtain a treatment liquid for
surface
treatment with a free fluorine concentration of 100 ppm (fluorine ion meter:
IM-55G,
manufactured by Toa Denpa Kogyo Co., Ltd.) and a pH value of 2.9. A test plate
that had been
degreased and water-washed was sprayed with the aforementioned surface
treatment liquid at
65 C for 300 seconds for surface treatment.
[0088] Actual Example 6
An aqueous zirconium nitrate solution, an aqueous hexafluoro titanium
solution,
lanthanum chloride, and iron nitrate were used to prepare a composition for
surface treatment
with a total mass concentration ratio K1 = B/A = 1.0 and a total mass
concentration ratio K2 =
C/A = 0.5. The aforementioned composition for surface treatment was diluted
with deionized
water to adjust the the mass concentration of the zirconium element and the
mass concentration
of the titanium element to a combined mass concentration of 200 ppm. Ammonium
fluoride and
potassium hydroxide were then used to obtain a treatment liquid for surface
treatment with a free
fluorine concentration of 50 ppm (fluorine ion meter: IM-55G, manufactured by
Toa Denpa
Kogyo Co., Ltd.) and a pH value of 4.2. A test plate that had been degreased
and water-washed
was immersed in the aforementioned surface treatment liquid at 60 C for 200
seconds for surface
treatment. After water washing, the plate was subjected to a post treatment.
As for the post
treatment liquid used, an aqueous hexafluoro titanium solution and nickel
nitrate were used to
prepare an aqueous solution with a titanium mass concentration of 200 ppm and
a nickel mass
27
CA 02591214 2007-06-08
concentration in terms of the metal element of 50 ppm. This aqueous solution
was heated to
45 C and then sodium hydroxide was used to adjust its pH to 4.5. The solution
thus obtained
was used in the post treatment.
[0089] Actual Example 7
An aqueous hexafluoro zirconium solution, yttrium sulfate, and nitric acid
were used to
prepare a composition for surface treatment with a total mass concentration
ratio K1 = B/A = 3.0
and a total mass concentration ratio K2 = C/A = 3Ø The aforementioned
composition for
surface treatment was diluted with deionized water to adjust the mass
concentration of the
zirconium element to 200 ppm. 50 ppm of EDTA was added to the liquid, then
hydrofluoric acid
and sodium hydroxide were used to obtain a treatment liquid for surface
treatment with a free
fluorine concentration of 80 ppm (fluorine ion meter: IM-55G, manufactured by
Toa Denpa
Kogyo Co., Ltd.) and a pH value of 2.8. A test plate that had been degreased
and water-washed
was used as a cathode and a carbon electrode was used as an anode to carry out
electrolysis
under an electrolysis condition [= current density -- Tr. Ed.] of 5A/dm2 in
the aforementioned
surface treatment liquid at room temperature for 10 seconds for surface
treatment.
[0090] Comparison Example 1
An aqueous zirconium nitrate solution and nitric acid were used to prepare a
composition
for surface treatment with a total mass concentration ratio K1 = B/A = 0.01
and a total mass
concentration ratio K2 = C/A = 10. The aforementioned composition for surface
treatment was
diluted with deionized water to adjust the mass concentration of the zirconium
element to 100
ppm. Sodium hydroxide was then used to obtain a treatment liquid for surface
treatment with a
pH value of 3Ø A test plate that had been degreased and water-washed was
immersed in the
aforementioned surface treatment liquid at 55 C for 180 seconds for surface
treatment.
28
CA 02591214 2007-06-08
[0091] Comparison Example 2
An aqueous hexafluoro zirconium solution, europium oxide, and sodium nitrate
were
used to prepare a composition for surface treatment with a total mass
concentration ratio K1 =
B/A = 5.0 and the total mass concentration ratio K2 = C/A = 200. The
aforementioned
composition for surface treatment was diluted with deionized water to adjust
the mass
concentration of the zirconium element to 4 ppm. Potassium fluoride and
potassium hydroxide
were then used to obtain a treatment liquid for surface treatment with a free
fluorine
concentration of 20 ppm (fluorine ion meter: IM-55G, manufactured by Toa Denpa
Kogyo Co.,
Ltd.) and a pH value of 3.8. A test plate that had been degreased and water-
washed was
immersed in the aforementioned surface treatment liquid at 60 C for 120
seconds for surface
treatment.
[0092] Comparison Example 3
An aqueous hexafluoro titanium solution, gallium sulfate, potassium nitrate,
and
ammonium nitrate were used to prepare a composition for surface treatment with
a total mass
concentration ratio K1 = B/A = 70 and a total mass concentration ratio K2 =
C/A = 50. The
aforementioned composition for surface treatment was diluted with deionized
water to adjust the
mass concentration of the titanium element to 50 ppm. Ammonium fluoride and
ammonia were
then used to obtain a treatment liquid for surface treatment with a free
fluorine concentration of
400 ppm (fluorine ion meter: IM-55G, manufactured by Toa Denpa Kogyo Co.,
Ltd.) and a pH
value of 2.8. A test plate that had been degreased and water-washed was
sprayed with the
aforementioned surface treatment liquid at 50 C for 150 seconds for surface
treatment.
[0093] Comparison Example 4
A test plate that had been degreased and water-washed was sprayed at room
temperature
29
CA 02591214 2013-02-01
for 30 seconds with a liquid obtained by diluting Preparen ZN (registered
trade name,
manufactured by the Nihon Parkerizing Co., Ltd.) (a surface preparation agent)
to 0.1% with
tap water. The test plate was then immersed in a zinc phosphate formation
treatment liquid at
43 C for deposition of a zinc phosphate film. The aforementioned zinc
phosphate formation
liquid was prepared as follows: Parbond L3020 (registered trade name,
manufactured by the
Nihon Parkerizing Co., Ltd.) was diluted with tap water to 4.8%. A sodium
hydrofluoride
reagent in a quantity equivalent to 200 ppm of fluorine was then added at 43 C
and the total
acidity and free acidity were adjusted to be central values of the catalogue
values provided.
[0094] Evaluation of Surface Coating Film and Measurement a Adhering Quantity
The external appearances of the test plates obtained in accordance with the
actual
examples and comparison examples after the surface treatment were evaluated
visually by the
naked eye and the adhering quantity of the surface coating film layer was
determined with the
use of a fluorescence X-ray analyzer (System 3270, manufactured by Rigaku
Denki Kogyo
Co., Ltd.).
[0095] Preparation of the Plate for Evaluation a Coating Performance
In order to evaluate the coating performance of the surface treatment plates
obtained
from the actual examples and comparison examples, the coating was carried out
according to
the following process: cation electrodeposition -) deionized water washing -)
baking ->
midcoat application -) baking -) topcoat application -) baking.
[0096] Cation Electrodeposition: epoxy-based cation electrodeposition coating
material (ElecronTM 9400, manufactured by Kansai Paint Co., Ltd.), voltage 200
V, film
thickness 20 gm, baking at 175 C for 20 minutes.
[0097] Midcoat Application: aminoalkyd-based coating material (AmilacTM TP-37
White,
CA 02591214 2007-06-08
,
,
manufactured by Kansai Paint Co., Ltd.), spray coating, film thickness 35 gm,
baking at 140 C
for 20 minutes.
[0098] Topcoat Application: aminoalkyd-based coating material (Amilac TM-13
Gray,
manufactured by Kansai Paint Co., Ltd.), spray coating, film thickness 35 gm,
baking at 140 C
for 20 minutes.
[0099] Coating Performance Evaluation
The coating performance of the actual examples and comparison examples was
evaluated
according to JIS specification. The evaluation items are described below. The
coated film
obtained at the time of completion of the electodeposition coating was called
the
electrodeposition coated film and the coated film obtained at the time of
completion of the
topcoat application was called a 3-coat coated film.
(i) Salt Spray Test: electrodeposition coated film
(ii) Adherence Test: 3-coat coated film
[0100] Salt Spray Test (SST)
A crosscut was made with the use of a sharp cutter on the electrodeposition
coating plate.
This plate was sprayed with 5% salt water for 720 hours (according to JIS-Z-
2371). After
spraying, the widths of the maximum swelling from both sides of the crosscut
area were
measured and evaluated according to the following evaluation standards:
Width of Maximum Swelling
no more than 5 mm : 111
greater than 5 mm but no more than 7 mm : 0
greater than 8 mm but no more than 9 mm : A
greater than 9 mm : x
31
CA 02591214 2007-06-08
[0101] Adherence Test (Crosscut Method)
A sharp cutter was used to make 6 cuts in both the vertical and horizontal
directions at 2
mm interval on the 3-coat coated film to obtain 25 squares (according to JIS-K-
5600-5-6). The
squares were peeled off by a tape and evaluated by the evaluation method
according to the
aforementioned JIS specification.
[0102] The results of evaluation of the external appearances of test plates
obtained from
the actual examples and comparison examples and the adhering quantity of the
surface coating
film are summarized in Table 1 and Table 2. The SPC materials and EG materials
obtained from
the actual examples all gave a uniform film and the targeted film adhering
quantity could be
attained. In contrast, the deposition of a surface coating film could not be
achieved on either the
SPC materials or the EG materials obtained from Comparison Example 1 because
of the small
value of the total mass concentration ratio Kl. Deposition of a surface
coating film was also not
possible on either the SPC material or the EG material obtained from
Comparison Example 2
because of the small content of component (A). Deposition of a surface coating
film was also
not possible on either the SPC material or the EG material obtained from
Comparison Example 3
because of the large value of the total mass concentration ratio K1 and the
high free fluorine ion
concentration D. Formation of a surface coating film was possible on the SPC
material and the
EG material obtained from Comparison Example 4 because a conventional zinc
phosphate
treatment was employed in this example.
[0103] Table 3 shows the results of coating performance evaluation of the
electrodeposition-coated film. The SPC material and EG material obtained from
the actual
examples all showed excellent corrosion resistance. In contrast, the promoting
effect of
component (B) on the film formation of component (A) was not sufficient in
Comparison
=
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CA 02591214 2007-06-08
Example 1 because of the small value of the total mass concentration ratio K1
. Accordingly,
there was not very much deposition of a surface coating film on either the SPC
material or the
EG material and the corrosion resistance of the deposited film was poor. For
the SPC material
and the EG material obtained from Comparison Example 2, the targeted adhering
quantity could
not be achieved and the corrosion resistance was poor because the content of
component (A) was
too low. For the SPC material and the EG material obtained from Comparison
Example 3, the
targeted adhering quantity could not be achieved and the corrosion resistance
was poor because
the total mass concentration ratio K1 was too large and the free fluorine ion
concentration D was
too high. In Comparison Example 4, a zinc phosphate treatment commonly used
for cation
electrodeposition coating was employed. The coating performances obtained from
the actual
examples were all superior to those obtained from Comparison Example 4 at all
levels.
[0104] Table 4 shows the results of evaluation of the adherence property of
the 3-coat
plate. The adherence property with regard to all the test plates used in the
actual examples was
excellent. For the comparison examples, as in the case of the corrosion
resistance of the
electrodeposition coated plate, the adherence property with regard to the test
plates used in all the
comparison examples except for Comparison Example 4 was not as good as that
obtained with
the actual examples.
[0105] It can be seen from the results mentioned above that, with the use of
the
composition for surface treatment, the treatment liquid for surface treatment,
the surface
treatment method, and the surface treated metal material of the present
invention, the deposition
of a surface coating film with excellent adherence and excellent corrosion
resistance becomes
possible.
[0106] [Table 1]
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External Appearance of Treatment Film
SPC EG
Actual Example 1 uniform interference color uniform interference color
Actual Example 2 uniform interference color uniform interference color
Actual Example 3 uniform interference color uniform interference color
Actual Example 4 uniform interference color uniform interference color
Actual Example 5 uniform interference color uniform interference color
Actual Example 6 uniform interference color uniform interference color
Actual Example 7 uniform interference color uniform interference color
Comparison Example 1 no deposition no deposition
Comparison Example 2 no deposition no deposition
Comparison Example 3 no deposition no deposition
Comparison Example 4 uniform gray color uniform gray color
[0107] [Table 2]
Total Adhesion Quantity of Component (A)
SPC EG
Actual Example 1 60 41
Actual Example 2 100 78
Actual Example 3 65 41
Actual Example 4 20 16
Actual Example 5 45 32
Actual Example 6 90 75
Actual Example 7 50 42
Comparison Example 1 6 3
Comparison Example 2 4 2
Comparison Example 3 5 3
Comparison Example 4 02.0 g/m2 E14.2 g/m2
Ei adhering quantity of zinc phosphate
[0108] [Table 3]
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CA 02591214 2007-06-08
Electrodeposition Plate, SST Results
SPC EG
Actual Example 1 El 0
Actual Example 2 El 0
Actual Example 3 El 0
Actual Example 4 CI 0
Actual Example 5 CI 0
Actual Example 6 El 0
Actual Example 7 CI 0
Comparison Example 1
Comparison Example 2
Comparison Example 3
Comparison Example 4 El 0
[01081 [Table 41
Adherence Property (Cross Cut Method)
CI Evaluation According to JIS K-5600-5-6
SPC EG
Actual Example 1 0 0
Actual Example 2 0 0
Actual Example 3 0 0
Actual Example 4 0 0
Actual Example 5 0 0
Actual Example 6 0 0
Actual Example 7 0 0
Comparison Example 1 2 1
Comparison Example 2 2 2
Comparison Example 3 2 2
Comparison Example 4 0 0
