U.S. patent application number 14/579148 was filed with the patent office on 2015-04-23 for di forming water-based coolant of laminated metal sheet and method of di forming laminated metal sheet.
The applicant listed for this patent is JFE Steel Corporation, Nippon Quaker Chemical, Ltd.. Invention is credited to Takeyoshi Fukuda, Toshikazu Ikeda, Hiroki Iwasa, Tomohiro Kanokogi, Junichi Kitagawa, Katsumi Kojima, Yasuhide Oshima, Masaki Tada, Yoshihiko Yasue.
Application Number | 20150107326 14/579148 |
Document ID | / |
Family ID | 41377205 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150107326 |
Kind Code |
A1 |
Oshima; Yasuhide ; et
al. |
April 23, 2015 |
DI FORMING WATER-BASED COOLANT OF LAMINATED METAL SHEET AND METHOD
OF DI FORMING LAMINATED METAL SHEET
Abstract
A method of DI forming a laminated metal sheet includes drawing
a laminated metal sheet; and redrawing and ironing the drawn
laminated metal sheet, wherein a water-based coolant including (a)
at least one base selected from the group consisting of
alkanolamines and alkali metal hydroxides, (b) a fatty acid, and
(c) water is used in the redrawing and ironing, and wherein a total
content of the base (a) and the fatty acid (b) is 0.02 to 4% by
mass and a ratio of a straight-chain fatty acid having a carbon
number of 6 to 12 in the fatty acid (b) is 80 to 100% by mass.
Inventors: |
Oshima; Yasuhide; (Tokyo,
JP) ; Tada; Masaki; (Tokyo, JP) ; Iwasa;
Hiroki; (Tokyo, JP) ; Kojima; Katsumi; (Tokyo,
JP) ; Kitagawa; Junichi; (Tokyo, JP) ; Yasue;
Yoshihiko; (Tokyo, JP) ; Ikeda; Toshikazu;
(Yao, JP) ; Kanokogi; Tomohiro; (Yao, JP) ;
Fukuda; Takeyoshi; (Yao, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JFE Steel Corporation
Nippon Quaker Chemical, Ltd. |
Tokyo
Yao |
|
JP
JP |
|
|
Family ID: |
41377205 |
Appl. No.: |
14/579148 |
Filed: |
December 22, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12993943 |
Nov 22, 2010 |
8962538 |
|
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PCT/JP2009/059937 |
May 26, 2009 |
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14579148 |
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Current U.S.
Class: |
72/342.5 |
Current CPC
Class: |
C10M 173/02 20130101;
C10N 2030/12 20130101; C09K 5/10 20130101; B21D 22/208 20130101;
B21D 22/201 20130101; C10N 2040/24 20130101; C10M 2207/125
20130101; C10M 2201/062 20130101; C10M 2215/042 20130101; C10N
2030/62 20200501; C10N 2020/091 20200501; C10M 2201/062 20130101;
C10N 2010/02 20130101; C10M 2201/062 20130101; C10N 2010/02
20130101 |
Class at
Publication: |
72/342.5 |
International
Class: |
B21D 22/20 20060101
B21D022/20 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 2008 |
JP |
2008-138741 |
Claims
1. A method of DI forming a laminated metal sheet comprising:
drawing a laminated metal sheet; and redrawing and ironing the
drawn laminated metal sheet, wherein a water-based coolant
comprising (a) at least one base selected from the group consisting
of alkanolamines and alkali metal hydroxides, (b) a fatty acid, and
(c) water is used in the redrawing and ironing, and wherein a total
content of the base (a) and the fatty acid (b) is 0.02 to 4% by
mass and a ratio of a straight-chain fatty acid having a carbon
number of 6 to 12 in the fatty acid (b) is 80 to 100% by mass.
2. The method according to claim 1, wherein a ratio of a
straight-chain fatty acid having a carbon number of 6 to 12 in the
fatty acid (b) is about 90 to 100% by mass.
3. The method according to claim 1, wherein pH of the water-based
coolant at 40.degree. C. is 7.3 to 11.5.
4. The method according to claim 1, wherein the at least one base
(a) is selected from the group consisting of ethanolamine or the
alkali metal hydroxides.
5. The method according to claim 1, wherein a molar ratio of the
base (a)/the fatty acid (b) is 0.42 to 4.1.
6. The method according to claim 1, wherein the straight-chain
fatty acid in the fatty acid (b) is at least one kind selected from
the group consisting of caproic acid, caprylic acid, and capric
acid.
7. The method according to claim 1, wherein a metal sheet
constituting the laminated metal sheet is a chromium steel sheet or
a tinned steel sheet.
8. A method of manufacturing a laminated DI-formed body by DI
forming a laminated metal sheet comprising: drawing a laminated
metal sheet into a cup; and redrawing and ironing the cup into the
laminated DI body, wherein a water-based coolant comprising (a) at
least one base selected from the group consisting of alkanolamines
and alkali metal hydroxides, (b) a fatty acid, and (c) water is
used in the redrawing and ironing, wherein a total content of the
base (a) and the fatty acid (b) is 0.02 to 4% by mass and a ratio
of a straight-chain fatty acid having a carbon number of 6 to 12 in
the fatty acid (b) is 80 to 100% by mass.
9. The method according to claim 8, wherein a ratio of a
straight-chain fatty acid having a carbon number of 6 to 12 in the
fatty acid (b) is about 90 to 100% by mass.
10. The method according to claim 8, wherein pH of the water-based
coolant at 40.degree. C. is 7.3 to 11.5.
11. The method according to claim 8, wherein the at least one base
(a) is selected from the group consisting of ethanolamine or the
alkali metal hydroxides.
12. The method according to claim 8, wherein a molar ratio of the
base (a)/the fatty acid (b) is 0.42 to 4.1.
13. The method according to claim 10, wherein the straight-chain
fatty acid in the fatty acid (b) is at least one kind selected from
the group consisting of caproic acid, caprylic acid, and capric
acid.
14. The method according to claim 8, wherein a metal sheet
constituting the laminated metal sheet is a chromium steel sheet or
a tinned steel sheet.
15. A method of manufacturing a laminated DI-formed body by DI
forming a laminated metal sheet comprising: drawing a laminated
metal sheet into a cup; and redrawing an ironing the cup into the
laminated DI body, wherein a water-based coolant comprising as
least (a) a base selected from the group consisting of
ethanolamines and alkali metal hydroxides, (b) a fatty acid, and
(c) water is used in the redrawing and ironing, wherein a total
content of the base (a) and the fatty acid (b) is 0.02 to 4% by
mass, a ratio of a straight-chain fatty acid having a carbon number
of 6 to 12 in the fatty acid (b) is about 90 to 100% by mass, pH of
the water-based coolant at 40.degree. C. is 7.3 to 11.5, and a
molar ratio of the base (a)/the fatty acid (b) is 0.42 to 4.1.
16. The method according to claim 15, wherein the straight-chain
fatty acid in the fatty acid (b) is at least one kind selected from
the group consisting of caproic acid, caprylic acid, and capric
acid.
17. The method according to claim 1, wherein the straight-chain
fatty acid in the fatty acid (b) has a carbon number of 6 to
10.
18. The method according to claim 8, wherein the straight-chain
fatty acid in the fatty acid (b) has a carbon number of 6 to
10.
19. The method according to claim 15, wherein the straight-chain
fatty acid in the fatty acid (b) has a carbon number of 6 to 10.
Description
RELATED APPLICATIONS
[0001] This is a divisional of U.S. Ser. No. 12/993,943, filed Nov.
22, 2010, which is a .sctn.371 of International Application No.
PCT/JP2009/059937, with an international filing date of May 26,
2009 (WO 2009/145338 A1, published Dec. 3, 2009), which is based on
Japanese Patent Application No. 2008-138741, filed May 27, 2008,
the subject matter of which is incorporated by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a DI forming water-based coolant
(lubricating/cooling agent) of a laminated metal sheet, a method of
DI forming a laminated metal sheet and a method of manufacturing a
laminated DI-formed body that uses the water-based coolant.
BACKGROUND
[0003] A DI can is one of two-piece cans that do not have a seam
between its body and bottom. The DI can is obtained by ironing or
redrawing/ironing a drawn can that is prepared by drawing a metal
sheet. The DI can is widely used as a container for beverages such
as beers and soft drinks and for foods such as soups and
vegetables.
[0004] The drawing herein is a method in which a metal sheet
punched into a disc is fixed using a blank holder and then formed
into a cup with its bottom using a tool constituted by punches and
dies in a drawing apparatus called a cupping press. The ironing is
a method of thinly stretching the side wall of a formed body (cup)
obtained by drawing or redrawing. A DI forming means a combination
between drawing and ironing or between drawing and
redrawing/ironing.
[0005] When the diameter of a metal sheet punched into a disc is
much larger than that of a punch in the drawing, it may be
difficult to obtain a cup having a desired shape in a single
drawing. In that case, the cup is generally formed into a desired
shape in a two-step drawing (drawing-redrawing). In that step, a
cup having a relatively large diameter is manufactured using a
drawing apparatus called a cupping press. Subsequently, redrawing
is performed and ironing is then performed using a can body forming
apparatus called a body maker.
[0006] Metal sheets such as a tinned steel sheet or an aluminum
sheet have been commonly used as a material of a metal sheet for DI
cans. After such metal sheets are DI formed into a desired shape,
aftertreatments such as cleaning, surface treatment, and coating
are performed to obtain a product (DI can). However, a method of
manufacturing a container product (DI can) by DI forming polyester
film (hereinafter may be simply referred to as "film") laminated
metal sheet (laminated metal sheet) has been considered recently to
omit or simplify the aftertreatments such as cleaning, surface
treatment, and coating.
[0007] DI forming methods are totally different between the case
where a film laminated metal sheet is DI formed and the case where
an existing metal sheet is used as a material.
[0008] As described in Japanese Unexamined Patent Application
Publication No. 9-271869, an emulsion coolant is commonly used in
the manufacturing of DI cans that uses an existing metal sheet as a
material. Since oil is dispersed in water in this emulsion coolant,
a chemical agent needs to be used for cleaning the oil left on a
can surface. This easily causes damage to a film, and thus the
existing emulsion coolant is unsuitable for DI forming of a
laminated metal sheet.
[0009] In recent years, a water-based coolant that is excellent in
ease of cleaning has been developed and commonly used as shown in
Japanese Unexamined Patent Application Publication Nos. 10-85872
and 10-88176. Since the water-based coolant is utilized for DI
forming that uses a metal sheet as a material, its viscosity is
increased with an ester of a trihydric alcohol and a fatty acid
having a carbon number of 18 (JP '872) or a polyoxyalkylene (JP
'176) to improve formability by reducing friction between a metal
surface and a forming tool.
[0010] However, when such a water-based coolant is utilized for DI
forming that uses a laminated metal sheet as a material, there are
various problems in that such a water-based coolant shows
insufficient DI formability, easily causes damage to a film, and
provides low food safety level of DI cans. Thus, such a water-based
coolant cannot be utilized for the DI forming.
[0011] Furthermore, when a water-based coolant is used, there is a
problem in that rust is easily caused on the surface of a forming
apparatus for DI forming.
[0012] A method for DI forming a laminated metal sheet is totally
different from a method for DI forming an existing metal sheet
because the surface of a metal sheet is coated with a laminate
film. In other words, the surface of the laminate film is softer
than that of a metal and also has lubricity. Thus, if a high
viscosity coolant containing polymers that is utilized for DI
forming of an existing metal sheet is used, the DI formability is
decreased.
[0013] A polyester film used for a laminated metal sheet is
slightly inferior in durability against a higher fatty acid having
a large number of carbon atoms. Adhesion of the polyester film to a
base material decreases and the film is damaged in contact with
such fatty acid having a large number of carbon atoms. In addition,
the food safety level of the existing coolant itself is low because
the existing coolant is used on the assumption that it is
completely removed in an aftertreatment such as a cleaning step
after DI forming.
[0014] Accordingly, it could be helpful to provide a DI forming
water-based coolant of a laminated metal sheet that achieves
excellent DI formability during DI forming of the laminated metal
sheet, and satisfies the following characteristics: (i) damage is
not caused to a lamination film (particularly polyester film) of
the laminated metal sheet; (ii) cleaning is easily performed and a
DI can with high food safety level can be obtained even if a
cleaning step of DI formed parts is simplified; and (iii) rust is
not easily caused on the surface of a forming apparatus in spite of
a water-based coolant.
[0015] It could also be helpful to provide a method for DI forming
a laminated metal sheet and a method of manufacturing a laminated
DI-formed body that use such a water-based coolant.
SUMMARY
[0016] We found that, by preparing a low viscosity water-based
solution that does not contain a polymer component used for an
existing DI forming coolant of a metal sheet, but contains a fatty
acid component having a small number of carbon atoms and by adding
multiple certain bases to the fatty acid, excellent DI formability
during the DI forming of a laminated metal sheet is achieved and a
DI forming coolant of a laminated metal sheet having the
characteristics (i) to (iii) described above is further
obtained.
[0017] We thus provide: [0018] [1] A DI forming water-based coolant
of a laminated metal sheet includes at least one kind of base (a)
selected from alkanolamines and alkali metal hydroxides, a fatty
acid (b), and water (c), wherein a total content of the base (a)
and the fatty acid (b) is 0.02 to 4% by mass and a ratio of a
straight-chain fatty acid having a carbon number of 6 to 12 in the
fatty acid (b) is 80 to 100% by mass. [0019] [2] In the DI forming
water-based coolant of a laminated metal sheet of [1], a molar
ratio of base (a)/fatty acid (b) is 0.2 to 3.0 while a molar ratio
of alkanolamine/fatty acid (b) is 0 to 3.0 and a molar ratio of
alkali metal hydroxide/fatty acid (b) is 0 to 1.8. [0020] [3] In
the DI forming water-based coolant of a laminated metal sheet of
[1] or [2], pH at 40.degree. C. is 7.3 to 11.5. [0021] [4] In the
DI forming water-based coolant of a laminated metal sheet of any
one of [1] to [3], the fatty acid (b) is at least one kind selected
from caproic acid, caprylic acid, capric acid, and lauric acid.
[0022] [5] In the DI forming water-based coolant of a laminated
metal sheet of any one of [1] to [4], an alkanolamine is contained
as at least part of the base (a), and the alkanolamine is at least
one kind selected from monoethanolamine and triethanolamine. [0023]
[6] In the DI forming water-based coolant of a laminated metal
sheet of any one of [1] to [5], an alkali metal hydroxide is
contained as at least part of the base (a), and the alkali metal
hydroxide is at least one kind selected from sodium hydroxide and
potassium hydroxide. [0024] [7] In a method of DI forming a
laminated metal sheet, the water-based coolant of any one of [1] to
[6] is used. [0025] [8] In the method of DI forming a laminated
metal sheet of [7], a metal sheet constituting the laminated metal
sheet is a chromium steel sheet or a tinned steel sheet. [0026] [9]
In a method of manufacturing a laminated DI-formed body by DI
forming a laminated metal sheet, the water-based coolant of any one
of [1] to [6] is used. [0027] [10] In the method of manufacturing a
laminated DI-formed body of [9], a metal sheet constituting the
laminated metal sheet is a chromium steel sheet or a tinned steel
sheet.
DETAILED DESCRIPTION
[0028] A DI forming water-based coolant of a laminated metal sheet
achieves excellent DI formability during DI forming of a laminated
metal sheet and has the following characteristics: (i) damage is
not caused to a lamination film (particularly polyester film) of
the laminated metal sheet; (ii) cleaning is easily performed and a
DI can with high food safety level can be obtained even if a
cleaning step of DI formed parts is simplified; and (iii) rust is
not easily caused on the surface of a forming apparatus in spite of
a water-based coolant. According to our method of DI forming a
laminated metal sheet and our method of manufacturing a laminated
DI-formed body that uses such a water-based coolant, DI forming of
a laminated metal sheet can be suitably performed and a laminated
DI-formed body (e.g., laminated DI can) with good quality, food
safety, and durability can be obtained. Since a cleaning step after
forming is simplified, productivity is significantly improved.
[0029] A DI forming water-based coolant of a laminated metal sheet
includes at least one kind of base (a) selected from alkanolamines
and alkali metal hydroxides, a fatty acid (b), and water (c),
wherein the total content of the base (a) and the fatty acid (b) is
0.02 to 4% by mass and the ratio of a straight-chain fatty acid
having a carbon number of 6 to 12 in the fatty acid (b) is 80 to
100% by mass.
[0030] The base (a) is composed of at least one kind of base
selected from alkanolamines and alkali metal hydroxides.
[0031] Examples of the alkanolamines include saturated aliphatic
amines having a hydroxyl group in its molecule. Alkanolamines
having a carbon number of 1 to 12 are preferably used, but the
alkanolamines are not particularly limited to the alkanolamines
having a carbon number of 1 to 12. Examples of the alkanolamines
having a carbon number of 1 to 12 include monomethanolamine,
dimethanolamine, trimethanolamine, N-ethylmethanolamine,
N-propylmethanolamine, N-n-butylmethanolamine,
N-tert-butylmethanolamine, N,N-diethylmethanolamine,
N,N-dipropylmethanolamine, N,N-di-n-butylmethanolamine,
N,N-di-tert-butylmethanolamine, monoethanolamine, diethanolamine,
triethanolamine, N-propylethanolamine, N-n-butylethanolamine,
N-tert-butylethanolamine, N,N-dimethylethanolamine,
N,N-dipropylethanolamine, N,N-di-n-butylethanolamine,
N,N-di-tert-butylethanolamine, monopropanolamine, dipropanolamine,
tripropanolamine, N-methylpropanolamine, N-ethylpropanolamine,
N-n-butylpropanolamine, N-tert-butylpropanolamine,
N,N-dimethylpropanolamine, N,N-diethylpropanolamine,
N,N-di-n-butylpropanolamine, and
N,N-di-tert-butylpropanolamine.
[0032] In consideration of solution stability of a water-based
coolant, ease of cleaning after DI forming, suppression of damage
to a lamination film (particularly a polyester film, hereinafter
the same) and the like, more preferable alkanolamines are
trimethanolamine, monoethanolamine, diethanolamine,
triethanolamine, and monopropanolamine. In consideration of ease of
cleaning after DI forming, suppression of damage to a lamination
film, and food safety, the most preferable alkanolamine is
monoethanolamine or triethanolamine.
[0033] One or more kinds of the alkanolamines can be used.
[0034] Examples of the alkali metal hydroxides include lithium
hydroxide, sodium hydroxide, potassium hydroxide, rubidium
hydroxide, cesium hydroxide, and francium hydroxide. In
consideration of solution stability of a water-based coolant, ease
of cleaning after DI forming, suppression of damage to a lamination
film, and food safety, the most preferable alkali metal hydroxide
is sodium hydroxide or potassium hydroxide.
[0035] One or more kinds of the alkali metal hydroxides can be
used.
[0036] Examples of the fatty acid (b) include aliphatic
monocarboxylic acids. A fatty acid having a carbon number of 2 to
34 is preferably used, but the fatty acid is not particularly
limited to the fatty acid having a carbon number of 2 to 34.
Examples of the fatty acid having a carbon number of 2 to 34
include butyric acid, valeric acid, caproic acid, enanthic acid,
caprylic acid, pelargonic acid, capric acid, undecanoic acid,
lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid,
palmitic acid, margaric acid, stearic acid, nonadecanoic acid,
arachidic acid, behenic acid, lignoceric acid, cerotic acid,
montanic acid, melissic acid, linoleic acid, linolenic acid,
.gamma.-linolenic acid, arachidonic acid, ricinoleic acid,
.alpha.-oxylinolenic acid, obtusilic acid, linoelaidic acid, oleic
acid, isovaleric acid, isobutyric acid, anteiso acid, licanic acid,
gorlic acid, hydrocarbyl acid, and malvalic acid.
[0037] In consideration of suppression of damage to a lamination
film, ease of cleaning after DI forming, and food safety, a
straight-chain fatty acid having a carbon number of 6 to 12 is more
preferable. Examples of the straight-chain fatty acid having a
carbon number of 6 to 12 include caproic acid, caprylic acid,
capric acid, and lauric acid. The most preferable straight-chain
fatty acid is caproic acid, caprylic acid, or capric acid. One or
more kinds of the fatty acids can be used.
[0038] Examples of the water (c) include tap water, ion-exchanged
water, and distilled water. In consideration of solution stability
of a water-based coolant, ease of cleaning after DI forming, and
suppression of damage to a lamination film, ion-exchanged water is
most preferable, but the water is not particularly limited to the
ion-exchanged water.
[0039] In the DI forming water-based coolant, the total content of
the base (a) and the fatty acid (b) is 0.02 to 4% by mass,
preferably 0.04 to 3.0% by mass, more preferably 0.06 to 2.0% by
mass, most preferably 0.07 to 1.5% by mass in consideration of DI
formability and corrosion resistance (soundness of a film of a can
inner surface). In other words, when the total content of the base
(a) and the fatty acid (b) falls below 0.02% by mass, corrosion
resistance (soundness of a film of a can inner surface) is
insufficient. When the total content exceeds 4% by mass, DI
formability (ease of stripping) is insufficient.
[0040] A neutralization reaction may be caused between the base (a)
and the fatty acid (b) in the DI forming water-based coolant.
[0041] In consideration of corrosion resistance (soundness of a
film of a can inner surface) and suppression of damage to a
lamination film, the ratio of the straight-chain fatty acid having
a carbon number of 6 to 12 in the fatty acid (b) is 80 to 100% by
mass, preferably 85 to 100% by mass. In other words, when the ratio
of the straight-chain fatty acid having a carbon number of 6 to 12
falls below 80% by mass, the damage to a film is significantly
large and corrosion resistance (soundness of a film of a can inner
surface) is insufficient.
[0042] The ratio (content) of the water (c) in the water-based
coolant is preferably 80% or more by mass, more preferably 85% or
more by mass, most preferably 90% or more by mass. When the ratio
of the water (c) falls below 80% by mass, DI formability, ease of
cleaning after DI forming, and suppression of damage to a film tend
to be insufficient.
[0043] With the DI forming water-based coolant of a laminated metal
sheet having the composition described above, excellent DI
formability is achieved during DI forming of a laminated metal
sheet. Furthermore, the DI forming water-based coolant of a
laminated metal sheet has the following characteristics: (i) damage
is not caused to a lamination film (particularly polyester film) of
the laminated metal sheet; (ii) cleaning is easily performed and a
DI can with high food safety level can be obtained even if a
cleaning step of DI formed parts is simplified; and (iii) rust is
not easily caused on the surface of a forming apparatus in spite of
a water-based coolant.
[0044] In the DI forming water-based coolant of a laminated metal
sheet, in consideration of corrosion resistance (soundness of a
film of a can inner surface), rust prevention of the surface of a
forming apparatus, ease of cleaning after DI forming, suppression
of damage to a lamination film, and solution stability of a
coolant, the molar ratio of base (a)/fatty acid (b) is preferably
0.2 to 3.0, more preferably 0.3 to 2.9, more preferably 0.4 to 2.8
while the molar ratio of alkanolamine/fatty acid (b) is preferably
0 to 3.0, more preferably 0.1 to 2.9, more preferably 0.2 to 2.8
and the molar ratio of alkali metal hydroxide/fatty acid (b) is
preferably 0 to 1.8, more preferably 0.1 to 1.7, more preferably
0.2 to 1.6.
[0045] In other words, when the molar ratio of base (a)/fatty acid
(b) falls below 0.2, corrosion resistance (soundness of a film of a
can inner surface), suppression of damage to a film, ease of
cleaning after DI forming, solution stability of a coolant, and
rust prevention of the surface of a forming apparatus tend to
decrease. In contrast, when the molar ratio exceeds 3.0, corrosion
resistance (soundness of a film of a can inner surface) tends to
decrease while damage is easily caused to a film. Furthermore, when
the molar ratio of alkanolamine/fatty acid (b) exceeds 3.0 in the
case where an alkanolamine is contained as part or all of the base
(a) or when the molar ratio of alkali metal hydroxide/fatty acid
(b) exceeds 1.8 when an alkali metal hydroxide is contained as part
or all of the base (a), damage is easily caused to a film.
[0046] In the DI forming water-based coolant of a laminated metal
sheet, in consideration of solution stability of a coolant,
corrosion resistance (soundness of a film of a can inner surface),
and the like, pH at 40.degree. C. is preferably 7.3 to 11.5, more
preferably 7.3 to 11.0, more preferably 7.5 to 10.5, most
preferably 7.5 to 9.5. In other words, when pH is less than 7.3,
solution stability of a coolant easily decreases and corrosion
resistance (soundness of a film of a can inner surface) also tends
to decrease. In contrast, when pH is more than 11.5, corrosion
resistance (soundness of a film of a can inner surface) tends to
decrease.
[0047] The DI forming water-based coolant of a laminated metal
sheet is required to contain the base (a), the fatty acid (b), and
the water (c), but other additional components can be added thereto
to improve the effects regarding DI formability, solution stability
of a coolant, rust prevention of the surface of a forming
apparatus, suppression of damage to a lamination film, ease of
cleaning after DI forming, food safety, and the like. Examples of
the other additional components include surfactants, cleaning
agents, dispersants, preservatives, antifoaming agents, and
sequestering agents. One or more kinds of these additional
components may be suitably blended.
[0048] Although the content of the additional components other than
(a) the base, (b) the fatty acid, and (c) the water is not limited,
the content is preferably 16% or less by mass in consideration of
the preferable content of (c) the water. Moreover, the content is
preferably 6% or less by mass in consideration of solution
stability of a coolant.
[0049] Nonionic surfactants, anionic surfactants, cationic
surfactants, or amphoteric surfactants can be used as the
surfactants. Among these, nonionic surfactants are particularly
preferred. Examples of the nonionic surfactants include
polyoxyethylene ether surfactants such as polyoxyethylene alkyl
ethers, block polyoxyethylene-polyoxypropylene alkyl ethers, random
polyoxyethylene-polyoxypropylene alkyl ethers, block
polyoxyalkylene glycols, random polyoxyalkylene glycols, block
polyoxyalkylene glycol alkyldiamines, and random polyoxyalkylene
glycol alkyldiamines; polyol fatty acid ester surfactants such as
sorbitan fatty acid esters, fatty acid sugar esters, glycerin fatty
acid esters, and pentaerythritol fatty acid esters; and
polyoxyethylene ester surfactants such as polyoxyethylene fatty
acid esters, sorbitan polyoxyethylene fatty acid esters, sorbitol
polyoxyethylene fatty acid esters, pentaerythritol polyoxyethylene
fatty acid esters, and polyoxyethylene castor oil esters. One or
more kinds of these nonionic surfactants can be used.
[0050] Nonionic surfactants and anionic surfactants can be used by
combining them. Publicly known cationic surfactants and amphoteric
surfactants can also be used.
[0051] In consideration of food safety, examples of more preferable
nonionic surfactants include polyoxyethylene ether surfactants such
as polyoxyethylene alkyl ethers, block
polyoxyethylene-polyoxypropylene alkyl ethers, random
polyoxyethylene-polyoxypropylene alkyl ethers, block
polyoxyalkylene glycols, random polyoxyalkylene glycols, block
polyoxyalkylene glycol alkyldiamines, and random polyoxyalkylene
glycol alkyldiamines; polyol fatty acid ester surfactants such as
sorbitan fatty acid esters, fatty acid sugar esters, glycerin fatty
acid esters, and pentaerythritol fatty acid esters; and
polyoxyethylene ester surfactants such as polyoxyethylene fatty
acid esters, sorbitan polyoxyethylene fatty acid esters, sorbitol
polyoxyethylene fatty acid esters, and polyoxyethylene castor oil
esters.
[0052] In consideration of food safety, examples of the cleaning
agents include alkali metal or alkaline-earth metal sulfonates,
alkali metal or alkaline-earth metal salicylates, alkali metal or
alkaline-earth metal phenates, and fatty acid soaps. One or more
kinds of these cleaning agents can be used.
[0053] Phenol preservatives, triazine preservatives, isothiazoline
preservatives, or the like are exemplified as the preservatives.
Examples of the phenol preservatives include o-phenylphenol,
Na-o-phenylphenol, and 2,3,4,6-tetrachlorophenol. Examples of the
triazine preservatives include
hexahydro-1,3,5-tris(2-hydroxyethyl)-1,3,5-triazine. Examples of
the isothiazoline preservatives include 1,2-benzisothiazolin-3-one,
5-chloro-2-methyl-4-isothiazolin-3-one, and
2-methyl-isothiazolin-3-one. One or more kinds of these
preservatives can be used.
[0054] In consideration of food safety, examples of more preferable
preservatives include o-phenylphenol, Na-o-phenylphenol,
hexahydro-1,3,5-tris(2-hydroxyethyl)-1,3,5-triazine,
1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one,
and 2-methyl-isothiazolin-3-one.
[0055] In consideration of food safety, examples of the antifoaming
agents include silicone emulsions, higher alcohols, metallic soaps,
and ethylene-propylene copolymers. One or more kinds of these
antifoaming agents can be used.
[0056] In a method of DI forming a laminated metal sheet, a
laminated metal sheet is DI-formed using the water-based coolant
described above. In a method of manufacturing a laminated DI-formed
body such as a DI can is manufactured by DI-forming a laminated
metal sheet using the water-based coolant described above.
[0057] For the method of DI forming a laminated metal sheet and the
method of manufacturing a laminated DI-formed body, the preferable
conditions or the like will be described hereinafter.
[0058] For example, a steel sheet, an aluminum sheet, or an
aluminum alloy sheet can be used as a material of the laminated
metal sheet, and an inexpensive steel sheet is preferred in
consideration of cost efficiency. For example, a chromium steel
sheet or a tinned steel sheet can be used as a base steel sheet to
be laminated. The chromium steel sheet (tin-free steel) preferably
has a metal chromium layer (upper layer) with a coating weight of
50 to 200 mg/m.sup.2 and a chromium oxide layer (lower layer) with
a coating weight of 3 to 30 mg/m.sup.2 on a metal chromium basis on
its surface. The tinned steel sheet preferably has a coating weight
of 0.5 to 15 g/m.sup.2. Although the thickness of the steel sheet
is not specifically limited, for example, a steel sheet having a
thickness of 0.15 to 0.30 mm can be suitably used.
[0059] A resin film (lamination film) constituting the laminated
metal sheet is preferably composed of a polyester resin film. The
water-based coolant is particularly useful when a laminated metal
sheet including such a resin film is DI formed.
[0060] The polyester resin film is inexpensive and has good
mechanical strength; good lubricity due to its low friction
coefficient; and a good shielding effect on a gas or a liquid, that
is, a good barrier property. Thus, the polyester resin film can
withstand forming with a high working ratio such as DI forming in
which an elongation percentage reaches 300%, and the film is sound
after the forming.
[0061] The polyester resin includes a dicarboxylic acid component
mainly composed of terephthalic acid and a diol component mainly
composed of ethylene glycol. In consideration of the balance
between processability and strength of the polyester resin film, 8
to 20 mol % of an isophthalic acid component is preferably
contained as a copolymer component. The crystallization temperature
is preferably 120 to 160.degree. C.
[0062] When the ratio of the copolymer component is low, molecules
are easily oriented. In addition, when the working ratio becomes
high, the film tends to be peeled off or a crack (breakage) in a
direction parallel to the height direction of a can tends to
appear. When a heat treatment is conducted on a processed can body,
molecules are also easily oriented. To make it difficult for
molecules to be oriented, the higher the ratio of the copolymer
component, the better. However, when the ratio exceeds 20 mol %,
the cost efficiency decreases due to expensive film cost.
Furthermore, scratch resistance and chemical resistance may
decrease because the film becomes soft.
[0063] Since a film resin is extremely easily crystallized if its
crystallization temperature is less than 120.degree. C., a crack or
a pin hole may appear in the film resin during processing with a
high working ratio. In contrast, since the crystallization kinetic
is extremely slow if its crystallization temperature is more than
160.degree. C., the film resin is not sufficiently crystallized
even in a heat treatment of 150.degree. C. or more and the strength
and durability of the film may be impaired.
[0064] Moreover, additives such as a pigment, a lubricant, and a
stabilizer may be added to the resin film. Another resin film
having a different function may be disposed between the resin film
and the upper layer or between the resin film and the base steel
sheet to provide two or more layers of resin films. A resin film
having a thickness of 5 to 50 .mu.m can be suitably used.
[0065] The laminated metal sheet normally has resin films such as
the polyester resin film described above on both faces thereof. A
method of laminating the resin to the metal sheet is not
particularly limited. Thermocompression bonding of a biaxially
stretched film or an unstretched film or extrusion in which a resin
film is directly formed on a metal sheet using a T-die can be
suitably selected. Furthermore, the polyester resin film can be
bonded to the base metal sheet using, for example, a
polyesterurethane adhesive or a saturated polyester adhesive.
Although it has been confirmed that all of the methods provide a
sufficient effect, the thermocompression bonding in particular is
advantageous in consideration of good adhesion to the base metal
sheet and cost efficiency because an adhesive is unnecessary.
[0066] In the DI forming of a laminated metal sheet, a commercially
available cupping press and DI press apparatus can be used, and
there is no difference made by their specifications. The DI forming
water-based coolant of a laminated metal sheet can be suitably used
for particularly ironing (and redrawing) with the DI press
apparatus. The coolant circulates through the apparatus to perform
cooling during forming.
[0067] The application of wax to the surface of a laminated metal
sheet is preferred as lubrication during drawing with the cupping
press. When 10 to 500 mg/m.sup.2 of paraffin wax or fatty acid
ester wax having a melting point of 30 to 80.degree. C. is applied,
good formability is provided.
[0068] The formed body obtained by forming with the DI press
apparatus is cleaned or not cleaned and then heat-treated to be
dried and improve adhesion of a film. The temperature in the heat
treatment is preferably 200.degree. C. or more. By drying the
formed body at a temperature of 200.degree. C. or more, almost all
components in the coolant disappear. As a result, a highly safe
laminated formed body (e.g., laminated DI can) is obtained. To
prevent degradation of the durability of a film, the temperature in
the heat treatment is preferably less than or equal to the melting
point of the resin film. In the case where cleaning is conducted
after DI forming, cleaning with water is sufficient.
EXAMPLE
[0069] A chromium steel sheet with a thickness of 0.20 mm and a
temper degree of T3 (metal chromium layer: 120 mg/m.sup.2, chromium
oxide layer: 10 mg/m.sup.2 on a metal chromium basis) was prepared
as a base steel sheet. A 10% isophthalic acid copolymerized
polyethylene terephthalate film having a thickness of 25 .mu.m and
made by biaxial stretching was pressure-bonded to both faces of the
base steel sheet that was heated to 240.degree. C. using a nip
roll, cooled with water within one second, and then dried to make a
laminated steel sheet to be a laminated DI can.
[0070] A laminated DI can was manufactured by DI forming the
thus-obtained laminated steel sheet under the conditions described
below. In the redrawing and ironing, water-based coolants shown in
Tables 1 to 3 were used. In this DI forming, 50 mg/m.sup.2 of
paraffin wax with a melting point of 45.degree. C. was applied to
both faces of the laminated steel sheet. Subsequently, a blank with
123 mm.phi. was punched and the blank was drawn into a cup having
an inner diameter of 71 mm.phi. and a height of 36 mm using a
commercially available cupping press. The cup was then inserted
into a commercially available DI press apparatus. Redrawing and
three-staged ironing (respective reductions are 20%, 19%, and 23%)
were conducted with a punch speed of 200 mm/s and a stroke of 560
mm. At the end, a laminated DI can having an inner diameter of 52
mm and a height of 90 mm was formed. In this DI forming, the
water-based coolants were circulated at 50.degree. C. Tap water was
used as water contained in the water-based coolants.
[0071] For the used water-based coolants, solution stability was
evaluated by the method described below. In addition, ease of
stripping during DI forming, corrosion resistance (soundness of a
film of a can inner surface) of a manufactured laminated DI can,
damage to a film, and eating quality were evaluated with
performance tests described below. For the evaluation of DI
formability and corrosion resistance after DI forming, the tests
were conducted after ion-exchanged water with a temperature of
50.degree. C. was sprayed to the obtained laminated DI can for two
minutes to clean the surface thereof and then dried in a drying
furnace at 210.degree. C. for 30 seconds. The evaluation results
are shown in Tables 1 to 3 together with the composition and
physical properties of the used water-based coolants.
(1) Solution Stability of Coolant
[0072] A solution condition after a coolant was held at 40.degree.
C. for one hour was visually observed to evaluate solution
stability. Evaluation criteria of the solution condition were Good:
transparent, Fair: translucent, and Poor: opaque.
(2): Ease of Stripping
[0073] A phenomenon in which, when a punch was pulled out from the
formed can body during DI forming, an opening edge of the can body
was caught by a stripper so that the opening edge was distorted was
evaluated as follows. [0074] Poor: Distortion that appears at the
opening edge reaches a trimming portion. [0075] Fair: Distortion
appears at the opening edge, but the distortion does not reach a
trimming portion. [0076] Good: Distortion appears at the opening
edge, but the distortion reaches only the border of the opening
edge. [0077] Excellent: There is no distortion at the opening
edge.
(3) Corrosion Resistance (Soundness of a Film of a can Inner
Surface)
[0078] Corrosion resistance was evaluated with the soundness of a
film of a can inner surface (a film having fewer defects is
better). After the mouth of a cleaned and dried laminated DI can
was scratched using a file such that an electric current can be
applied to its base steel sheet, the can was filled with an
electrolyte solution (1% NaCl solution, 25.degree. C.) to the mouth
of the can. Subsequently, a voltage of 6.2 V was applied between
the can body and the electrolyte solution. The evaluation was
performed on the basis of the measured current value as described
below. [0079] Poor: more than 1 mA [0080] Fair: more than 0.1 mA
and 1 mA or less [0081] Good: more than 0.01 mA and 0.1 mA or less
[0082] Excellent: 0.01 mA or less
(4) Damage to Film
[0083] The damage caused by coolants was evaluated for a formed
film of a can inner surface. A cleaned and dried laminated DI can
was filled with coolants having each composition and a lid was then
seamed to the can. Retort treatment (125.degree. C., 90 minutes)
was conducted on the can and the lid was then opened. After the
mouth of the can was scratched using a file such that an electric
current can be applied to its base steel sheet, the can was filled
with an electrolytic solution (1% NaCl solution, 25.degree. C.) to
the mouth of the can. Subsequently, a voltage of 6.2 V was applied
between the can body and the electrolytic solution. The evaluation
was performed on the basis of the measured current value as
described below. [0084] Poor: more than 5 mA [0085] Fair: more than
0.5 mA and 5 mA or less [0086] Good: more than 0.05 mA and 0.5 mA
or less [0087] Excellent: 0.05 mA or less
(5) Eating Quality
[0088] The presence or absence of coolant components left on a can
inner surface after heat treatment was evaluated with a sensory
test. After flanging was conducted on a heat-treated laminated DI
can, the can was filled with pure water to the mouth of the can.
The lid was then seamed to the can and retort treatment
(125.degree. C., 90 minutes) was conducted. Five testers conducted
the sensory test on the water in the can after the retort treatment
and evaluated as follows. [0089] Poor: Two or more testers out of
five sense a nasty smell or a taste difference. [0090] Good: One or
none of the testers out of five senses a nasty smell or a taste
difference.
TABLE-US-00001 [0090] TABLE 1 Coolant Composition Base (a) Fatty
acid (b) Water (c) Content Content (a) + (b) (a)/(b) Content Other
additional (% by (% by (% by (molar (% by components No. Kind mass)
Kind *1 mass) mass) ratio) mass) Component 1 triethanolamine 0.38
caprylic acid (C8) 0.16 0.54 2.38 99.46 -- 2 triethanolamine 0.38
capric acid (C10) 0.19 0.57 2.38 99.43 -- 3 triethanolamine 1.90
caproic acid (C6) 0.50 2.40 2.95 97.60 -- 4 triethanolamine 0.38
lauric acid (C12) 0.22 0.60 2.33 99.40 -- 5 triethanolamine 1.36
caprylic acid (C8) 0.47 1.83 2.79 98.17 -- 6 triethanolamine 0.02
capric acid (C10) 0.03 0.05 0.97 99.95 -- 7 triethanolamine 2.40
lauric acid (C12) 1.10 3.50 2.93 96.50 -- 8 triethanolamine 0.01
caproic acid (C6) 0.01 0.02 0.92 99.98 -- 9 triethanolamine 0.04
caprylic acid (C8) 0.04 0.08 0.92 99.92 -- 10 sodium hydroxide 0.01
capric acid (C10) 0.05 0.06 0.85 99.94 -- 11 sodium hydroxide 0.01
caprylic acid (C8) 0.04 0.05 0.82 99.95 -- 12 monoethanolamine 0.17
capric acid (C10) 0.20 0.37 2.40 99.63 -- 13 monoethanolamine 0.21
caprylic acid (C8) 0.17 0.38 2.97 99.62 -- 14 potassium hydroxide
0.06 caprylic acid (C8) 0.18 0.24 0.87 99.76 -- 15 potassium
hydroxide 0.06 capric acid (C10) 0.21 0.27 0.88 99.73 -- 16
potassium hydroxide 0.08 caprylic acid (C8) 0.20 0.28 1.02 99.72 --
17 potassium hydroxide 0.005 caproic acid (C6) 0.02 0.025 0.47
99.975 -- 18 potassium hydroxide 0.96 lauric acid (C12) 2.80 3.76
1.05 96.24 -- 19 potassium hydroxide 0.004 caproic acid (C6) 0.02
0.024 0.41 99.976 -- 20 triethanolamine 0.38 undecanoic acid (C11)
0.21 0.59 2.26 99.41 -- Coolant Composition Other additional
components Physical properties Content Solution Can manufacturing
evaluation (% by pH stability Ease of Corrosion Damage Eating No.
mass) (40.degree. C.) (40.degree. C.) stripping resistance to film
quality Section 1 -- 8.5 Good Excellent Excellent Excellent Good
Example 2 -- 8.6 Good Excellent Excellent Excellent Good Example 3
-- 8.9 Good Excellent Excellent Excellent Good Example 4 -- 8.4
Good Excellent Excellent Excellent Good Example 5 -- 8.8 Good
Excellent Excellent Excellent Good Example 6 -- 7.6 Good Excellent
Excellent Excellent Good Example 7 -- 8.8 Good Excellent Excellent
Excellent Good Example 8 -- 7.5 Good Excellent Excellent Excellent
Good Example 9 -- 7.4 Good Excellent Excellent Excellent Good
Example 10 -- 11.2 Good Excellent Excellent Excellent Good Example
11 -- 11.1 Good Excellent Excellent Excellent Good Example 12 --
10.3 Good Excellent Excellent Excellent Good Example 13 -- 10.8
Good Excellent Excellent Excellent Good Example 14 -- 7.6 Good
Excellent Excellent Excellent Good Example 15 -- 7.9 Good Excellent
Excellent Excellent Good Example 16 -- 11.3 Good Excellent
Excellent Excellent Good Example 17 -- 7.7 Good Excellent Excellent
Excellent Good Example 18 -- 11.4 Good Excellent Excellent
Excellent Good Example 19 -- 7.4 Good Excellent Excellent Excellent
Good Example 20 -- 8.2 Good Excellent Excellent Excellent Good
Example *1 The number in parentheses is the number of carbon
atoms.
TABLE-US-00002 TABLE 2 Coolant Composition Base (a) Fatty acid (b)
Water (c) Content Content (a) + (b) (a)/(b) Content Other
additional (% by (% by (% by (molar (% by components No. Kind mass)
Kind *1 mass) mass) ratio) mass) Component 21 triethanolamine 0.48
enanthic acid (C7) 0.18 0.66 2.33 99.34 -- 22 potassium hydroxide
0.20 enanthic acid (C7) 0.55 0.75 0.84 99.25 -- 23 triethanolamine
0.38 caprylic acid (C8) + 0.17 0.55 2.38 99.45 -- capric acid (C10)
*4 24 triethanolamine 0.027 caprylic acid (C8) 0.035 0.062 0.75
99.938 -- 25 triethanolamine 0.22 capric acid (C10) 0.45 0.67 0.56
99.33 -- 26 monoethanolamine 0.05 capric acid (C10) 0.04 0.09 4.10
99.91 -- 27 potassium hydroxide 0.07 capric acid (C10) 0.19 0.26
1.13 99.74 -- 28 potassium hydroxide 0.08 caprylic acid (C8) 0.58
0.66 0.35 99.34 -- 29 triethanolamine 0.38 caprylic acid (C8) 0.16
0.54 2.38 99.16 polyoxyalkylene glycol *2 30 triethanolamine 0.38
capric acid (C10) 0.19 0.57 2.38 99.13 polyoxyalkylene glycol *3 31
triethanolamine 0.39 fatty acid A *5 0.15 0.54 2.42 99.46 -- 32
triethanolamine 0.392 fatty acid B *6 0.186 0.578 2.39 99.422 -- 33
potassium hydroxide 0.06 fatty acid B *6 0.22 0.28 0.90 99.72 -- 34
base A *7 0.037 caprylic acid (C8) 0.11 0.147 0.85 99.853 -- 35
base B *8 0.435 capric acid (C10) 0.21 0.645 2.41 99.355 -- Coolant
Composition Other additional components Physical properties Content
Solution Can manufacturing evaluation (% by pH stability Ease of
Corrosion Damage Eating No. mass) (40.degree. C.) (40.degree. C.)
stripping resistance to film quality Section 21 -- 8.3 Good
Excellent Excellent Excellent Good Example 22 -- 7.8 Good Excellent
Excellent Excellent Good Example 23 -- 8.5 Good Excellent Excellent
Excellent Good Example 24 -- 7.6 Good Excellent Excellent Excellent
Good Example 25 -- 6.2 Fair Excellent Good Excellent Good Example
26 -- 14.0 Good Excellent Good Good Good Example 27 -- 13.5 Good
Excellent Good Excellent Good Example 28 -- 6.1 Fair Excellent Good
Excellent Good Example 29 0.30 8.3 Good Excellent Excellent
Excellent Good Example 30 0.30 8.5 Good Excellent Excellent
Excellent Good Example 31 -- 8.7 Good Excellent Excellent Excellent
Good Example 32 -- 8.6 Good Excellent Excellent Excellent Good
Example 33 -- 8.0 Good Excellent Excellent Excellent Good Example
34 -- 7.8 Good Excellent Excellent Excellent Good Example 35 -- 8.6
Good Excellent Excellent Excellent Good Example *1 The number in
parentheses is the number of carbon atoms. *2 "Pluronic PE 6400"
available from BASF Japan *3 "Pluronic PE 4300" available from BASF
Japan *4 Mixing ratio (by mass) = 1:1 *5 "LUNAC 8-98" available
from Kao Corporation (=caprylic acid (C8): 98% or more by mass) *6
"LUNAC 10-98" available from Kao Corporation (=capric acid (C10):
98% or more by mass) *7 triethanolamine: 1% by mass + potassium
hydroxide: 99% by mass *8 triethanolamine: 99% by mass + potassium
hydroxide: 1% by mass
TABLE-US-00003 TABLE 3 Coolant Composition Base (a) Fatty acid (b)
Water (c) Content Content (a) + (b) (a)/(b) Content Other
additional (% by (% by (% by (molar (% by components No. Kind mass)
Kind *1 mass) mass) ratio) mass) Component 36 triethanolamine 0.057
fatty acid D *13 0.0245 0.0815 2.41 99.9185 -- 37 potassium
hydroxide 0.12 fatty acid D *13 0.37 0.49 0.86 99.51 -- 38 base C
*10 0.025 caprylic acid (C8) 0.026 0.051 1.36 99.949 -- 39 base D
*11 0.029 caprylic acid (C8) 0.026 0.055 2.17 99.945 -- 40 base E
*12 0.011 caprylic acid (C8) 0.026 0.037 0.42 99.963 -- 41
triethanolamine 0.45 caprylic acid (C8) 0.14 0.59 3.11 99.41 -- 42
monoethanolamine 0.16 capric acid (C10) 0.15 0.31 3.06 99.69 -- 43
base B *8 0.24 capric acid (C10) 0.08 0.32 3.48 99.68 -- 44
triethanolamine 3.84 oleic acid (C18) 3.03 6.87 2.40 93.13 -- 45
potassium hydroxide 0.03 oleic acid (C18) 0.35 0.38 0.43 99.62 --
46 triethanolamine 0.38 butyric acid (C4) 0.09 0.47 2.49 99.53 --
47 triethanolamine 0.0009 caprylic acid (C8) 0.0008 0.0017 1.09
99.9983 -- 48 triethanolamine 4.70 capric acid (C10) 2.10 6.80 2.58
93.20 -- 49 potassium hydroxide 0.0003 caprylic acid (C8) 0.0009
0.0012 0.86 99.9988 -- 50 triethanolamine 0.33 oleic acid (C18)
0.25 0.58 2.50 99.42 -- 51 triethanolamine 0.21 fatty acid C *9
0.12 0.33 2.45 99.67 -- 52 sodium hydroxide 0.049 fatty acid C *9
0.21 0.259 0.88 99.741 -- 53 triethanolamine 0.20 fatty acid E *14
0.10 0.30 2.42 99.70 -- 54 potassium hydroxide 0.0038 fatty acid E
*14 0.01 0.0138 1.24 99.9862 -- Coolant Composition Other
additional components Physical properties Content Solution Can
manufacturing evaluation (% by pH stability Ease of Corrosion
Damage Eating No. mass) (40.degree. C.) (40.degree. C.) stripping
resistance to film quality Section 36 -- 8.5 Good Excellent
Excellent Excellent Good Example 37 -- 7.6 Good Excellent Excellent
Excellent Good Example 38 -- 12.6 Good Excellent Good Good Good
Example 39 -- 9.7 Good Excellent Excellent Excellent Good Example
40 -- 8.4 Good Excellent Excellent Excellent Good Example 41 -- 9.1
Good Excellent Excellent Good Good Example 42 -- 11.2 Good
Excellent Good Good Good Example 43 -- 9.3 Good Excellent Excellent
Good Good Example 44 -- 8.2 Good Poor Good Poor Good Comparative
Example 45 -- 7.0 Poor Excellent Poor Poor Good Comparative Example
46 -- 8.8 Good Excellent Poor Good Good Comparative Example 47 --
8.1 Good Excellent Poor Good Good Comparative Example 48 -- 8.6
Good Poor Excellent Excellent Good Comparative Example 49 -- 8.2
Good Excellent Poor Good Good Comparative Example 50 -- 8.4 Good
Excellent Poor Poor Good Comparative Example 51 -- 8.8 Good
Excellent Poor Poor Good Comparative Example 52 -- 8.0 Good
Excellent Poor Poor Good Comparative Example 53 -- 8.6 Good
Excellent Poor Poor Good Comparative Example 54 -- 12.3 Good
Excellent Poor Poor Good Comparative Example *1 The number in
parentheses is the number of carbon atoms. *8 triethanolamine: 99%
by mass + potassium hydroxide: 1% by mass *9 capric acid (C10): 50%
by mass + linoleic acid (C18): 50% by mass *10 triethanolamine: 50%
by mass + potassium hydroxide: 50% by mass *11 triethanolamine: 20%
by mass + potassium hydroxide: 80% by mass *12 triethanolamine: 95%
by mass + potassium hydroxide: 5% by mass *13 "LUNAC 8-98"
available from Kao Corporation (=caprylic acid (C8): 98% or more by
mass): 90% by mass + oleic acid (C18): 10% by mass *14 "LUNAC 8-98"
available from Kao Corporation (=caprylic acid (C8): 98% or more by
mass): 70% by mass + linoleic acid (C18): 30% by mass
[0091] According to Tables 1 to 3, when the water-based coolants
No. 1 to 43 of Invention Example were used, good results were
obtained for all the DI formability (ease of stripping and
corrosion resistance), the damage to a film, and the eating
quality. In contrast, when the water-based coolants No. 44 to 54 of
Comparative Example were used, at least one of the DI form ability
(ease of stripping and corrosion resistance), the damage to a film,
and the eating quality was insufficient.
[0092] When the water-based coolants of Invention Example were
used, an effect of rust prevention was produced on the surface of a
steel material of a DI forming apparatus. Furthermore, problems
such as rusting did not arise even in a long-term use or a
long-term contact of the coolants.
INDUSTRIAL APPLICABILITY
[0093] A DI forming water-based coolant of a laminated metal sheet
achieves excellent DI formability during DI forming of a laminated
metal sheet and has the following characteristics: (i) damage is
not caused to a lamination film (particularly polyester film) of
the laminated metal sheet; (ii) cleaning is easily performed and a
DI can with high food safety level can be obtained even if a
cleaning step of DI formed parts is simplified; and (iii) rust is
not easily caused on the surface of a forming apparatus in spite of
a water-based coolant. Accordingly, in a method of DI forming a
laminated metal sheet and a method of manufacturing a laminated
DI-formed body that use the water-based coolant described above, a
laminated metal sheet can be suitably DI formed to obtain a
laminated DI-formed body (e.g., laminated DI can) with good
quality, food safety, and durability. Since a cleaning step after
forming is simplified, productivity is significantly improved.
Thus, the coolant and method has significantly high industrial
applicability.
* * * * *