U.S. patent application number 11/756851 was filed with the patent office on 2007-11-29 for composition for metal surface treatment, treating liquid for surface treatment, method of surface treatment, and surface-treated metal material.
Invention is credited to Katsuyuki Kawakami, Masayuki Yoshida.
Application Number | 20070272900 11/756851 |
Document ID | / |
Family ID | 36577866 |
Filed Date | 2007-11-29 |
United States Patent
Application |
20070272900 |
Kind Code |
A1 |
Yoshida; Masayuki ; et
al. |
November 29, 2007 |
Composition for Metal Surface Treatment, Treating Liquid for
Surface Treatment, Method of Surface Treatment, and Surface-Treated
Metal Material
Abstract
A surface-treating composition which is a treating liquid
containing no ingredients harmful to the environment; such a
treating liquid has been difficult to obtain with any conventional
technique. The composition enables a coating film having excellent
corrosion resistance after coating to be deposited through surface
treatment on a surface of a metallic material, e.g., an iron-based
metallic material. The composition, which is for the surface
treatment of a metal comprising iron and/or zinc, comprises the
following ingredients (A), (B), and (C): (A) a compound containing
at least one element selected from the group consisting of
titanium, zirconium, hafnium, and silicon; (B) a compound
containing yttrium and/or a lanthanide element; and (C) nitric acid
and/or a nitric acid compound. In the composition, the ratio of the
total mass concentration B of the yttrium and/or lanthanide element
in the ingredient (B) to the total mass concentration A of the
element(s) in the ingredient (A), K1=B/A, is
0.05.ltoreq.K1.ltoreq.50 and the ratio of the total mass
concentration C of nitrogen atoms in the ingredient (C) in terms of
NO.sub.3 concentration to the total mass concentration A, K2=C/A,
is 0.01.ltoreq.K2.ltoreq.200.
Inventors: |
Yoshida; Masayuki;
(Okayama-Pref., JP) ; Kawakami; Katsuyuki; (Tokyo,
JP) |
Correspondence
Address: |
HENKEL CORPORATION
THE TRIAD, SUITE 200
2200 RENAISSANCE BLVD.
GULPH MILLS
PA
19406
US
|
Family ID: |
36577866 |
Appl. No.: |
11/756851 |
Filed: |
June 1, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP05/22176 |
Dec 2, 2005 |
|
|
|
11756851 |
Jun 1, 2007 |
|
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Current U.S.
Class: |
252/387 ;
427/435 |
Current CPC
Class: |
C23C 22/34 20130101;
C25D 9/08 20130101; C23C 22/83 20130101; C25D 5/34 20130101; C23C
22/50 20130101; C25D 9/10 20130101; C23C 22/53 20130101 |
Class at
Publication: |
252/387 ;
427/435 |
International
Class: |
C23F 11/00 20060101
C23F011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2004 |
JP |
2004-356059 |
Claims
1. A composition for the surface treatment of metals that
comprises: (A) a compound containing at least one element selected
from the group consisting of Ti, Zr, Hf, and Si; (B) a compound
containing yttrium and/or a lanthanide element; (C) nitric acid
and/or a nitric acid compound; and (D) an optional component of at
least one fluorine-containing compound.
2. The composition for surface treatment as claimed in claim 1,
having a ratio "K1" of total mass concentration "B" of the yttrium
and/or lanthanide element of Component (B) to total mass
concentration "A" of the at least one element of Component (A) in
the range of 0.05.ltoreq.K1.ltoreq.50 and a ratio "K2"of the total
mass concentration "C" of the nitrogen atoms contained in Component
(C), in terms of the NO.sub.3 concentration, to the total mass
concentration "A", in the range of 0.01.ltoreq.K2.ltoreq.200.
3. The composition for surface treatment as claimed in claim 1
comprising a treatment liquid that contains Component (D), at least
one fluorine-containing compound, in an amount such that the free
fluorine ion concentration "D" is in the range of 0.001
ppm<D<300 ppm.
4. The treatment liquid for surface treatment as claimed in claim 3
having a pH value no greater than 6.0.
5. The treatment liquid for surface treatment as claimed in claim 3
further comprising at least one compound selected from a group
consisting of HCl, H.sub.2SO.sub.4, HClO.sub.3, HBrO.sub.3,
HNO.sub.2, HMnO.sub.4, HVO.sub.3, H.sub.2O.sub.2, H.sub.2WO.sub.4,
H.sub.2MoO.sub.4, and their salts in a concentration in the range
of 10-20,000 ppm.
6. The treatment liquid for surface treatment as claimed in claim 3
further comprising at least one compound selected from a 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.
7. The treatment liquid for surface treatment as claimed in claim 3
further comprising at least one water-soluble polymer compound
and/or a water-dispersible polymer compound.
8. The treatment liquid for surface treatment as claimed in claim 3
further comprising at least one surfactant selected from a group
consisting of nonionic surfactants, anionic surfactants, and
cationic surfactants.
9. A treatment method for metal material comprising iron and/or
zinc comprising: contacting a metal material comprising iron and/or
zinc with an acidic treatment liquid that comprises: (A) a compound
containing at least one element selected from the group consisting
of Ti, Zr, Hf, and Si; (B) a compound containing yttrium and/or a
lanthanide element present in an amount such that ratio "K1" of
total mass concentration "B" of the yttrium and/or lanthanide
element of Component (B) to total mass concentration "A" of the at
least one element of Component (A) is in the range of
0.05.ltoreq.K1.ltoreq.50; (C) nitric acid and/or a nitric acid
compound present in an amount such that ratio "K2" of the total
mass concentration "C" of the nitrogen atoms contained in Component
(C), in terms of the N0.sub.3 concentration, to the total mass
concentration "A", is in the range of 0.01.ltoreq.K2.ltoreq.200;
and (D) at least one fluorine-containing compound in an amount such
that the free fluorine ion concentration "D" in the treatment
liquid is in the range of 0.001 ppm.ltoreq.D.ltoreq.300 ppm.
10. The surface treatment method as claimed in claim 9 in which the
metal material containing iron and/or zinc is contacted with the
treatment liquid thereby simultaneously carry out a degreasing
treatment and a film formation treatment of said metal
material.
11. The surface treatment method as claimed in claim 9 in which the
metal material containing iron and/or zinc is a metal material that
has been cleansed by a degreasing treatment.
12. The surface treatment method as claimed in claim 9 in which the
treatment liquid contact process comprises an electrolytic
treatment using the metal material containing iron and/or zinc as
the cathode.
13. The surface treatment method as claimed in claim 9 further
comprising a step of contacting the metal material with an aqueous
solution containing at least one element selected from a group
consisting of cobalt, nickel, tin, copper, titanium, and zirconium
after the treatment liquid contact process.
14. The surface treatment method as claimed in claim 9 further
comprising a step of contacting the metal material with an aqueous
solution containing a water-soluble polymer compound or a
water-dispersible polymer compound after the treatment liquid
contact process.
15. An iron-containing metal material having a surface coating film
layer, that is formed on the surface of the iron-containing metal
material by a surface treatment method as claimed in claim 9, said
surface coating film layer comprising at least one element of
Component (A) in an amount of greater than 20 mg/cm.sup.2.
16. A zinc-containing metal material having a surface coating film
layer, that is formed on the surface of the zinc-containing metal
material by a surface treatment method as claimed in claim 9, said
surface coating film layer comprising at least one element of
Component (A) in an amount of greater than 15 mg/cm.sup.2.
17. A surface treatment method comprising contacting a metal
material containing iron and/or zinc with the treatment liquid for
surface treatment as claimed in claim 3.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation under 35 USC Sections
365(c) and 120 of International Application No. PCT/JP2005/022176,
filed Dec. 2, 2005 and published Jun. 15, 2006 as WO 2006/062037
Al, which claims priority from Japanese Application No. JP
2004-356059 filed Dec. 8, 2004, which is incorporated herein by
reference in its entirety.
FIELD OF THE INVENTION
[0002] 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.
DISCUSSION OF THE RELATED ART
[0003] The phosphoric acid zinc treatment method or the chromate
treatment method is commonly used for deposition of a surface
coating film on the surface of metal materials, which provides the
metal with excellent corrosion resistance after coating. With the
phosphoric acid zinc treatment method, a film providing 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.
[0004] However, the formation of sludge as a byproduct during the
phosphoric acid zinc treatment is difficult to avoid. 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.
[0005] Therefore, techniques have been developed in recent years to
provide the 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 in
the prior art.
[0006] For example, in the method described in Japanese Patent
Application No. 2000-204,485, a non-chrome coating for metal
surface treatment that contains a compound having a nitrogen atom
with a lone electron pair or that contains this nitrogen 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 compositions that contain no harmful
hexavalent chromium.
[0007] 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.
[0008] In the method described in Japanese Patent Application No.
2[1990]-25,579, 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.
[0009] The use of this method, as in the case of the method
described in Japanese Patent Application No. 2000-204,485, 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.
[0010] In the method described in Japanese Patent Application No.
2000-199,077, a metallic surface treatment 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. 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 Japanese Patent
Application No. 5[1993]-195,244. 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. However, with
this method, the film is formed by coating and drying as in the
case of the method described in Japanese Patent Application No.
2000-204,485 and thus it is difficult to achieve a uniform film
coating on a material with a complex structure.
[0012] In Japanese Patent Application No. 2004-43913, 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. However, this method requires using an oxidizing
agent for controlling the iron ion concentration in the chemical
conversion agent during the conversion process. Therefore, this
method cannot be used to carry out a highly workable surface
treatments 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.
SUMMARY OF THE INVENTION
[0013] 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
deposited on a metal surface provides bare corrosion resistance as
well as excellent corrosion resistance after additional surface
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.
[0014] Applicants 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 techniques. The problems of the prior art discussed
above are solved, at least in part, by the present inventions as
described in below.
[0015] It is an object of the invention to provide a composition
for the surface treatment of metals that comprise iron and/or zinc,
the composition comprising: [0016] (A) a compound containing at
least one element selected from the group consisting of Ti, Zr, Hf,
and Si; [0017] (B) a compound containing yttrium and/or a
lanthanide element; and [0018] (C) nitric acid and/or a nitric acid
compound.
[0019] In one embodiment of the composition, the ratio "K1" of the
total mass concentration "B" of the yttrium and/or lanthanide
element contained in Component (B) to the total mass concentration
"A" of elements contained in Component (A), i.e., K1=B/A, is in the
range of 0.05.ltoreq.K1.ltoreq.50 and the ratio "K2" of the total
mass concentration "C" of the nitrogen atoms contained in Component
(C) in terms of the NO.sub.3 concentration to total mass
concentration "A", i.e., K2=C/A, is in the range of
0.01.ltoreq.K2.ltoreq.200.
[0020] A composition for surface treatment as described herein may
also comprise Component (D), at least one fluorine-containing
compound. Desirably, the free fluorine ion concentration "D" is in
the range of 0.001 ppm.ltoreq.D.ltoreq.300 ppm.
[0021] A treatment liquid as described herein desirably has a pH
value of no more than 6.0. [0019.] It is a further object of the
invention to provide a composition for the surface treatment of
metals that comprise iron and/or zinc, as described above, the
composition also comprising at least one compound selected from the
group consisting of HCl, H.sub.2SO.sub.4, HClO.sub.3, HBrO.sub.3,
HNO.sub.2, HMnO.sub.4, HVO.sub.3, H2O.sub.2, H.sub.2WO.sub.4,
H.sub.2MoO.sub.4 and their salts in a concentration in the range of
10-20,000 ppm.
[0022] It is a further object of the invention to provide a
composition for the surface treatment of metals that comprise iron
and/or zinc, as described above, 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 1-1 0,000 ppm.
[0023] It is a further object of the invention to provide a
composition for the surface treatment of metals that comprise iron
and/or zinc, as described above, that contains a water-soluble
polymer compound and/or a water- dispersible polymer compound.
[0024] It is a further object of the invention to provide a
composition for the surface treatment of metals that comprise iron
and/or zinc, as described above, that contains at least one
surfactant selected from a group consisting of nonionic
surfactants, anionic surfactants, and cationic surfactants.
[0025] It is an object of the invention to provide 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 herein.
[0026] It is a further object of the invention to provide a surface
treatment method for metals containing iron and/or zinc as
described above, 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 to simultaneously carry out
a degreasing treatment and a film formation treatment on metal
material. In another embodiment, metal material that contains iron
and/or zinc is a metal material that has been cleansed by a
degreasing treatment.
[0027] It is a further object of the invention to provide a surface
treatment method as described herein, in which treatment liquid
contact process involves an electrolytic treatment using metal
material that contains iron and/or zinc as a cathode.
[0028] It is a further object of the invention to provide a surface
treatment method as described herein that includes a process in
which the 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 treatment liquid
contact process.
[0029] It is a further object of the invention to provide a surface
treatment method as described herein that includes a process in
which the 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
treatment liquid contact process.
[0030] Another object of the invention is an iron-containing metal
material having a surface coating film layer, formed on the surface
thereof by a surface treatment method as described herein, using a
composition that contains the elements of Component (A) and the
surface coating film layer has an adhesion quantity in terms of
elements of greater than 20 mg/cm.sup.2 or greater than 15
mg/cm.sup.2.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0031] 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 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 conventional techniques.
[0032] 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.
[0033] 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.
[0034] The materials to be surface-treated with the treatment
liquid of the present invention are iron-based metal materials or
zinc-based metal materials.
[0035] 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, steel
plate such as cold rolled steel plate, hot rolled steel plate,
etc., cast iron, and sintered materials.
[0036] 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.
[0037] 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, riveting or other known methods. The
functions of the present invention will now be described in
detail.
[0038] A composition of the present invention contains Component
(A), Component (B), and Component (C) as described below.
[0039] 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(SO.sub.4).sub.2,
TiOSO.sub.4, Ti(NO.sub.3).sub.4, TiO(NO.sub.3).sub.2, Ti(OH).sub.4,
TiO.sub.2OC.sub.2O.sub.4, H.sub.2TiF.sub.6, salts of
H.sub.2TiF.sub.6, TiO, TiO.sub.2, Ti.sub.2O.sub.3, TiF.sub.4,
ZrCl.sub.4, ZrOCl.sub.2, Zr(OH).sub.2C1.sub.2, Zr(OH).sub.3CI,
Zr(SO.sub.4).sub.2, ZrOSO.sub.4, Zr(NO.sub.3).sub.4,
ZrO(NO.sub.3).sub.2, Zr(OH).sub.4, H.sub.2ZrF.sub.6, salts of
H.sub.2ZrF.sub.6, H.sub.2(Zr(CO.sub.3).sub.2(OH).sub.2, salts of
H.sub.2(Zr(CO.sub.3).sub.2(OH).sub.2,
H.sub.2Zr(OH).sub.2(SO.sub.4).sub.2, salts of
H.sub.2Zr(OH).sub.2(SO.sub.4).sub.2, ZrO.sub.2, ZrOBr.sub.2,
ZrF.sub.4, HfCl.sub.4, Hf(SO.sub.4).sub.2, H.sub.2HfF.sub.6, salts
of H.sub.2HfF.sub.6, HfO.sub.2, HfF.sub.4, H.sub.2SiF.sub.6, salts
of H.sub.2SiF.sub.6 and A1.sub.2O.sub.3(SiO.sub.2).sub.3. Two or
more of these compounds may also be used together.
[0040] Component (B) is a compound containing yttrium 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, suitable compounds
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 together.
[0041] Component (C) comprises nitric acid and/or a nitric acid
compound. Suitable compounds include, for example, nitric acid,
metal nitrates, and the like. Metal nitrates 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.
[0042] A composition of the present invention is diluted with water
or dissolved in water to form a treatment liquid at the time of its
use for the surface treatment of a metal. 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 elements (Ti, Zr, Hf. and Si) of Component (A)
within the range of 10 ppm to 10,000 ppm.
[0043] The term "the total mass concentration "A" of elements
contained in Component (A)" indicates "the concentration of
elements contained in Component (A) contained in the composition
(in some cases, the treatment liquid) of the present invention".
The terms "the total mass concentration B" and "the total mass
concentration C" are interpreted in a like manner for their
respective components.
[0044] In the composition for surface treatment and the treatment
liquid for surface treatment of the present invention, the ratio
"K1" of the total mass concentration "B" of the yttrium and/or
lanthanide element contained in Component (B) to the total mass
concentration "A" of the elements contained in Component (A), i.e.,
K1=B/A, is in the range of 0.05.ltoreq.K1.ltoreq.50 and the ratio
"K2"of the total mass concentration "C" of the nitrogen atoms
contained in Component (C) in terms of the NO.sub.3 concentration
to the total mass concentration "A", i.e., K2=C/A, is in the range
of 0.01.ltoreq.K2.ltoreq.200.
[0045] 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.
[0046] 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.
[0047] 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).
[0048] When 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., K1, is within the range of
0.05.ltoreq.K1<50 and the corrosion resistance of the treated
metal material may decrease.
[0049] When K 1 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 where
the ratio of B/A is outside of the above recited ranges.
[0050] When 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.
[0051] When K2=C/A is in the range of 0.01.ltoreq.K2.ltoreq.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.
[0052] The total mass concentration "A" of 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 or 100 ppm to 4,000
ppm. When the 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 KI and K2 are within the specified ranges.
When the 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.
[0053] 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, H.sub.2TiF.sub.6, salts of
H.sub.2TiF.sub.6, TiF.sub.4, H.sub.2ZrF.sub.6, salts of
H.sub.2ZrF.sub.6, ZrF.sub.4, H.sub.2HfF.sub.6, salts of
H.sub.2HfF.sub.6, HfF.sub.4, H.sub.2SiF.sub.6, HBF.sub.4, salts of
HBF.sub.4, NaHF.sub.2, KHF.sub.2, NH.sub.4HF.sub.2, NaF, KF, and
NH.sub.4F. Two or more of these fluorine-containing compounds may
also be used concomitantly.
[0054] 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 in a manner
known in the art, see the Examples. 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.
[0055] 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 4.0.
[0056] 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 hydroxide, barium
hydroxide, alkali metal salts, ammonia, ammonium salts, and amines
may be used.
[0057] 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.
[0058] 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, HCl, H.sub.2SO.sub.4, HClO.sub.3,
HBrO.sub.3, HNO2, HMnO.sub.4, HVO.sub.3, H.sub.2O.sub.2,
H.sub.2WO.sub.4, H.sub.2MoO.sub.4, and the like. 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; preferably 20 tol5,000; most preferably 50 to 10,000
ppm, is sufficient for providing the desired effect.
[0059] 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; preferably 10 ppm to 9,000 ppm; most
preferably 20 ppm to 7,500 ppm, is sufficient for providing the
desired effect. [0058.] 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 compounds added, but a concentration
in the range of 1 ppm to 10,000 ppm; preferably 10 to 9,000; most
preferably 20 to 7,500 ppm, is preferable. This addition quantity
should give a sufficient effect.
[0060] 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.
[0061] 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.
[0062] The only requirement of the surface treatment method of the
present invention is to contact the metal material containing iron
and/or zinc with the treatment liquid of the present invention. In
this way a film made of oxides and/or hydroxides of the elements of
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.
[0063] Any method such as a spray treatment, immersion treatment,
or other treatment methods know in the art can be used for the
contact treatment mentioned above; the contact method used will not
affect the performance of the film formed.
[0064] It is chemically difficult to obtain the hydroxide of metals
contained in the film of Component (A) in the form of a pure
hydroxide. In general, therefore, oxides of the metals with
attached water of hydration are also included in this group of
oxides. Therefore, the 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.
[0065] The 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.
[0066] As mentioned before, when the treatment liquid of the
present invention contains surfactant, a good film can be formed
even without pre-cleansing of the 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 metal
material containing iron and/or zinc are carried out at the same
time.
[0067] There are no particular limitations with regard to the
conditions of use of the treatment liquid of the present
invention.
[0068] The reactivity of the treatment liquid of the present
invention can be controlled freely by changing the ratio "K1"of the
total mass concentration "B" to the total mass concentration "A",
i.e., K1=B/A, and the ratio "K2" of the total mass concentration
"C" to the total mass concentration "A", i.e., K2=C/A.
[0069] Furthermore, even when at least one of 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.
[0070] In the treatment method of the present invention, an
electrolytic treatment with the metal material containing iron
and/or zinc as the cathode can be carTied 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 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.
[0071] After the metal material containing iron and/or zinc has
made contact with the treatment liquid of the present invention or
has been subjected to an electrolytic treatment during 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.
[0072] 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.
[0073] There are no particular limitations with regard to the
source of supply of the 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 metal elements can be
used. The acidic aqueous solution containing the 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, ammonia, ammonium salts, and amines can be used for pH
adjustment.
[0074] The 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.
[0075] 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 Component (A) or a film layer made of a mixture of
film layers consisting of the film layer of Component (A) and a
film layer made of the oxides and/or hydroxides of the metal
elements of Component (B). Here, any films made of the oxides
and/or hydroxides of Component (A) are acid and alkali resistant
and are chemically stable.
[0076] 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 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 metal to be
treated and thus the superior effect of the present invention can
be maintained even in a corrosive environment.
[0077] 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.
[0078] In addition to Component (A) and Component (B), the
composition and the treatment liquid of the present invention may
also contain Component (C), the proportions 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.
[0079] Here, in order to utilize the 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/m.sup.2,
more preferably greater than 30 mg/m.sup.2, and especially greater
than 40 mg/m.sup.2.
[0080] 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 amount of the
surface coating film in terms of Component (A) is preferably
greater than 15 mg/m.sup.2, and more preferably greater than 20
mg/m.sup.2.
[0081] When the adhering amount is too small, the barrier effect
will not be sufficient and it will be difficult to obtain excellent
corrosion resistance.
[0082] 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/m.sup.2, and especially no more than 800 mg/m.sup.2.
[0083] The invention and its benefits will be better understood
with reference to the following examples. These examples are
intended to illustrate specific embodiments within the overall
scope of the invention as claimed, and are not to be understood as
limiting the invention in any way.
ACTUAL EXAMPLES
[0084] 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.
Plates Used for the Study
[0085] The code designations and description of the plates used in
the actual examples and comparison examples are given below. [0086]
SPC (cold rolled steel plate; JIS-G-3141) [0087] EG (zinc
electroplated steel plate; plating quantity 20 g/m.sup.2) Treatment
Process
[0088] The surface treatment in Actual Examples 1-5 and Comparison
Examples 1-3 was carried out in accordance with the following
treatment process: Alkaline degreasing.fwdarw.water
washing.fwdarw.film formation treatment.fwdarw.water washing
deionized.fwdarw.water washing drying.
[0089] In Actual Example 6, the surface treatment was carried out
in accordance with the following treatment process: Alkaline
degreasing.fwdarw.water washing.fwdarw.film formation
treatment.fwdarw.water washing.fwdarw.post
treatment.fwdarw.deionized water washing.fwdarw.drying.
[0090] In Actual Example 7, the surface treatment was carried out
in accordance with the following treatment process: Alkaline
degreasing.fwdarw.water washing.fwdarw.electroformation
treatment.fwdarw.water washing.fwdarw.deionized water
washing.fwdarw.drying.
[0091] In Comparison Example 4, the surface treatment was carried
out in accordance with the following treatment process: Alkaline
degreasing.fwdarw.water washing.fwdarw.surface
preparation.fwdarw.water washing.fwdarw.deionized water
washing.fwdarw.drying.
[0092] 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.degree. C. for 120 seconds.
[0093] 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.
[0094] The plate was then dried by allowing it to stand in a room
at room temperature.
Actual Example 1
[0095] 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. This composition for
surface treatment was diluted with deionized water to adjust the
mass concentration of the zirconium to 8,000 ppm. Sodium hydroxide
was then added 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 surface treatment liquid at 50.degree. C. for 180
seconds for surface treatment.
Actual Example 2
[0096] 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 composition for
surface treatment was diluted with deionized water to adjust the
mass concentration of the zirconium to 100 ppm. Hydrofluoric acid
and ammonia were then added to obtain a surface treatment liquid
with a free fluorine concentration of 25 ppm (as measured according
to the manufacturer's instructions with 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 surface treatment liquid at 45.degree. C. for 150 seconds for
surface treatment.
Actual Example 3
[0097] 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
ratio K1=B/A=5.0 and a total mass concentration ratio K2=C/A=20.
The composition for surface treatment was diluted with deionized
water to adjust the mass concentration of the zirconium and the
mass concentration of hafnium to a combined mass concentration of
50 ppm. 100 ppm of succinic acid was added to the liquid thus
obtained. Potassium fluoride and lithium hydroxide were added 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 4.0. A
test plate that had been degreased and water-washed was immersed in
the surface treatment liquid at 60.degree. C. for 120 seconds for
surface treatment.
Actual Example 4
[0098] 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 composition for surface
treatment was diluted with deionized water to adjust the mass
concentration of the zirconium to 20 ppm. Hydrofluoric acid and
calcium hydroxide were then added 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 3.0. A test plate that had been degreased
and water-washed was sprayed with the surface treatment liquid at
55.degree. C. for 120 seconds for surface treatment.
Actual Example 5
[0099] An aqueous titanium nitrate solution, an aqueous hexafluoro
silicate solution, praseodymium oxide, and potassium nitrate were
used to prepare a composition for surface treatment with a total
mass concentration ratio K1=B/A=0.4 and a total mass concentration
ratio K2=C/A=8.0. The composition for surface treatment was diluted
with deionized water to adjust the mass concentration of the
zirconium and the mass concentration of the silicon to a combined
mass concentration of 2,500 ppm. Ammonium fluoride and ammonia were
then added 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 surface treatment liquid at 65.degree. C. for 300
seconds for surface treatment.
Actual Example 6
[0100] 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 composition for surface treatment was diluted with
deionized water to adjust the mass concentration of the zirconium
and the mass concentration of the titanium to a combined mass
concentration of 200 ppm. Ammonium fluoride and potassium hydroxide
were then added 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 surface treatment liquid at 60.degree. 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 concentration in terms
of the metal element of 50 ppm. This aqueous solution was heated to
45.degree. C. and then sodium hydroxide was used to adjust its pH
to 4.5. The solution thus obtained was used in the post
treatment.
Actual Example 7
[0101] 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=3.0. The composition for
surface treatment was diluted with deionized water to adjust the
mass concentration of the zirconium to 200 ppm. 50 ppm of EDTA was
added to the liquid, then hydrofluoric acid and sodium hydroxide
were added 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 cathodic electro deposition at a current
density of 5 A/dm.sup.2 in the surface treatment liquid at room
temperature for 10 seconds for surface treatment.
Comparison Example 1
[0102] 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 composition for surface
treatment was diluted with deionized water to adjust the mass
concentration of the zirconium to 100 ppm. Sodium hydroxide was
then added to obtain a treatment liquid for surface treatment with
a pH value of 3.0. A test plate that had been degreased and
water-washed was immersed in the surface treatment liquid at
55.degree. C. for 180 seconds for surface treatment.
Comparison Example 2
[0103] 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 composition
for surface treatment was diluted with deionized water to adjust
the mass concentration of the zirconium to 4 ppm. Potassium
fluoride and potassium hydroxide were then added 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
surface treatment liquid at 60.degree. C. for 120 seconds for
surface treatment.
Comparison Example 3
[0104] 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 composition for surface treatment was diluted with deionized
water to adjust the mass concentration of the titanium to 50 ppm.
Ammonium fluoride and ammonia were then added 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 surface treatment
liquid at 50.degree. C. for 150 seconds for surface treatment.
Comparison Example 4
[0105] A test plate that had been degreased and water-washed was
sprayed at room temperature for 30 seconds with a liquid obtained
by diluting Prepalene 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.degree. C. for
deposition of a zinc phosphate film. The zinc phosphate formation
liquid was prepared as follows: Palbond 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 to the
diluted Palbond at 43.degree. C. and the total acidity and free
acidity were adjusted to the specified values provided by the
Palbond manufacturer for use.
Evaluation of Surface Coating Film and Measurement of Adhering
Quantity
[0106] 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. The
adhering quantity of the surface coating film layer in g/m.sup.2
was determined with the use of a fluorescence X-ray analyzer
(System 3270, manufactured by Rigaku Denki Kogyo Co., Ltd.) as in
known in the art.
Preparation of the Plate for Evaluation of Coating Performance
[0107] 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.fwdarw.deionized water
washing.fwdarw.baking.fwdarw.midcoat
application.fwdarw.baking.fwdarw.topcoat application.fwdarw.baking.
[0108] Cation Electrodeposition: epoxy-based cation
electrodeposition coating material (Elecron 9400, manufactured by
Kansai Paint Co., Ltd.), voltage 200 V, film thickness 20 .mu.m,
baking at 175.degree. C. for 20 minutes. [0109] Midcoat
Application: aminoalkyd-based coating material (Amilac TP-37 White,
manufactured by Kansai Paint Co., Ltd.), spray coating, film
thickness 35 .mu.m, baking at 140.degree. C. for 20 minutes.
Topcoat Application: aminoalkyd-based coating material (Amilac TM-
13 Gray, manufactured by Kansai Paint Co., Ltd.), spray coating,
film thickness 35 .mu.m, baking at 140.degree. C. for 20 minutes.
Coating Performance Evaluation
[0110] The coating performance of the actual examples and
comparison examples was evaluated according to the above mentioned
JIS specification. The evaluation items are described below. The
coated film obtained at the time of completion of the
electrodeposition 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. [0111] (i)
Salt Spray Test: electrodeposition coated film [0112] (ii)
Adherence Test: 3-coat coated film Salt Spray Test (SST)
[0113] 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: TABLE-US-00001 Width of Maximum Swelling no
more than 5 mm .circleincircle. greater than 5 mm but no more than
7 mm .largecircle. greater than 8 mm but no more than 9 mm .DELTA.
greater than 9 mm X
Adherence Test (Crosscut Method)
[0114] 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). Adhesive
tape was applied to the cut surface and then removed as per JIS
specification. Any squares were peeled off by a tape and evaluated
by the evaluation method according to the JIS specification.
[0115] 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.
[0116] 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 "K1". 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.
[0117] 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 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.
[0118] 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 "K 1" 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.
[0119] 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.
[0120] 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. TABLE-US-00002
TABLE 1 External Appearance of Treatment Film SPC EG Actual Example
1 uniform interference color uniform surface color Actual Example 2
uniform interference color uniform surface color Actual Example 3
uniform interference color uniform surface color Actual Example 4
uniform interference color uniform surface color Actual Example 5
uniform interference color uniform surface color Actual Example 6
uniform interference color uniform surface color Actual Example 7
uniform interference color uniform surface color Comparison no
deposition no deposition Example 1 Comparison no deposition no
deposition Example 2 Comparison no deposition no deposition Example
3 Comparison uniform gray color uniform gray color Example 4
[0121] TABLE-US-00003 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 .asterisk-pseud.2.0 g/m.sup.2 .asterisk-pseud.4.2
g/m.sup.2 .asterisk-pseud.adhering quantity of zinc phosphate
[0122] TABLE-US-00004 TABLE 3 Electrodeposition Plate, SST Results
SPC EG Actual Example 1 .circleincircle. .largecircle. Actual
Example 2 .circleincircle. .largecircle. Actual Example 3
.circleincircle. .largecircle. Actual Example 4 .circleincircle.
.largecircle. Actual Example 5 .circleincircle. .largecircle.
Actual Example 6 .circleincircle. .largecircle. Actual Example 7
.circleincircle. .largecircle. Comparison Example 1 X X Comparison
Example 2 X X Comparison Example 3 X X Comparison Example 4
.circleincircle. .largecircle.
[0123] TABLE-US-00005 TABLE 4 Adherence Property (Cross Cut Method)
.asterisk-pseud.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
[0124] This invention relates to a composition for surface
treatment, and processes for using this product. It can be used in
many variations of the processes that are employed industrially.
While the invention has been described in terms of specific
embodiments thereof, it will be appreciated that other forms could
readily be adapted by one skilled in the art. Accordingly, the
scope of the invention is to be considered limited only by the
following claims.
* * * * *