Note: Descriptions are shown in the official language in which they were submitted.
20~40~5
BACKGROUND OF THE INVENIION
The present invention relates to a surfactant composition, and
a degreasing composition and a degreasing bath containing the surfactant
5 composition, and more particularly to a surfactant composition suitable
for a degreasing composition having excellent detergency and
antifoaming properties at room temperature, and a degreasing
composition and a degreasing bath containing such surfactant
composition.
In the chemical coating of metal surfaces, degreasing is
usually conducted to remove oil substances (mineral oils, animal or
vegetable fats and oils, etc.) from the surfaces of metal members to be
formed with chemical coatings.
Degreasing detergents used for degreasing treatments contain
15 as main components builders based on acids or alkalis and nonionic
surfactants, and they are used in the form of aqueous solutions by a
spraying method or an immersion method at 40 - 70C for 1 - 10
minutes.
However, in view of the recent demands of saving energy,
2 0 detergents capable of removing oils at lower temperatures such as S
40C are desired.
As such detergents, Japanese Patent Laid-Open No. 61-60892
discloses an alkali detergent usable at room temperature which contains
polyoxyalkylene alkyl ether as a surfactant. The polyoxyalkylene alkyl
25 ether in this detergent has the following general formula:
RO(EO)m(PO)nH,
wherein R: Alkyl group,
E 0: Ethylene oxide group,
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2~14085
PO: Propylene oxide group, and
m,n: Moles.
However, although this detergent has improved detergency at
room Itemperature, the level of detergency is still insufficient.
OBJECTS AND SUMMAR~ OF THE INVENTION
Accordingly, an object of the present invention is to provide a
surfactant composition having excellent detergency at room temperature
which is equal to or even higher than under heated conditions (40C or
10 higher), with little foaming.
Another object of the present invention is to provide a
degreasing composition having excellent detergency at room temperature
which is equal to or even higher than under heated conditions (40C or
higher), with little foaming.
A further object of the present invention is to provide a
degreasing bath having excellent detergency at room temperature which
is equal to or even higher than under heated conditions (40C or higher),
with little foaming.
A still further object of the present invention is to provide a
2 0 degreasing composition and a degreasing bath showing excellent
detergency even when oil materials are accumulated.
As a result of intense research in view of the above objects,
the inventors of the present invention have found that a surfactant
composition obtained by mixing a polyoxyalkylene ether-type nonionic
2 5 surfactant containing a predetermined amount of ethylene group with a
phosphate-polyethylene oxide adduct shows excellent detergency and
antifoaming properties at room temperature when combined with an
alkali builder. The present invention is based upon this finding.
- 2 -
Thus, the surfactant composition according to the present
invention comprises a compound (a) represented by the general formula:
R1O(AO)nH,
wherein R I is a substituted or unsubstituted hydrocarbon group having 6
S or more carbon atoms; A is at least one group selected from the group
consisting of an ethylene group, a propylene group, a butylene group and
a styrene group, provided that an ethylene group in A is S mol or more
per 1 mol of Rl, and that the ethylene group is 50 mol % or more per 100
mol % of the A; and n is an integer of 5 - 50; and
10 a compound (b) represented by the general formula:
O
2 11
(R )x P(O(EO)n)y H,
wherein R2 is a substituted or unsubstituted hydrocarbon group having 6
15 or more carbon atoms, E is an ethylene group, n is an integer of 1 - 20, x
and y are 1 or 2, and x ~ y = 3,
in a weight ratio of compound (a)/compound (b) = 10/90 - 95/5.
The degreasing composition according to the present
invention comprises a compound (a) represented by the general formula:
2 0 RlO(AO)nH,
wherein Rl is a substituted or unsubstituted hydrocarbon group having 6
or more carbon atoms; A is at least one group selected from the group
consisting of an ethylene group, a propylene group, a butylene group and
a styrene group, provided that an ethylene group in A is S mol or more
2~ per 1 mol of Rl, and that the ethylene group is 50 mol % or more per 100
mol % of the A; and n is an integer of 5 - 50; and
a compound (b) represented by the general formula:
2 ll
(R )x P(O(EO)n) y H,
wherein R2 is a substituted or unsubstituted hydrocarbon group having 6
5 or more carbon atoms, E is an ethylene group, n is an integer of 1 - 20, x
and y are 1 or 2, and x + y = 3,
in a weight ratio of compound (a)/compound (b) = 10/90 - 95/S, and
further comprising an allcali builder in a weight ratio [(compound (a) +
compound (b)3/alkali builder] of 1:0.1 - 1:2,000.
The degreasing bath according to the present invention
comprises:
(1) 0.005 - 0.5 weight % of a surfactant composition comprising:
a compound (a) represented by the general formula:
RlO(AO),~H,
wherein Rl is a substituted or unsubstituted hydrocarbon group
having 6 or more carbon atoms; A is at least one group selected
from the group consisting of an ethylene group, a propylene group,
a butylene group and a styrene group, provided that an ethylene
group in A is S mol or more per 1 mol of Rl, and that the ethylene
group is 50 mol % or more per 100 mol % of the A; and n is an
integer of 5 - 50; and
a compound (b) represented by the general formula:
o
(R2 )X P(O~EO)n) y H,
~
wherein R2 is a substituted or unsubstituted hydrocarbon group
having 6 or more carbon atoms, E is an ethylene group, n is an
integerofl -20,xandyarel or2,andx+y=3,
~ 014085
in a weight ratio of compound (a~/compound (b) - lO/90 - 95/5;
and
(2) 0.05 - lO weight % of an alkali builder.
5 DETArLl~D DESCRIPTION OF THE lNVENTION
The compound (a) used in the pIesent invention is
represented by the following general formula (l):
RlO(AO)nH, ... (1)
wherein n is an integer of 5 - 50.
l O In the above general formula (l), Rl is, as described below in
detail, a hydrocarbon group having 6 or more carbon atoms. When the
number of carbon atoms is 5 or less, sufficient surfactant activity cannot
be obtained, failing to provide good detergency.
"A" in the above general formula (l) is at least one group
l 5 selected from the group consisting of an ethylene group, a propylene
group, a butylene group and a styrene group. Incidentally, the number
of the ethylene group in "A" is 5 mol or more per l mol of Rl. When the
ethylene group is less than 5 mol, the resulting surfactant composition
does not have sufficient detergency. Further, the proportion of the
20 ethylene group in "A" is 50 mol % or more per lOO mol % of "A." When
the proportion of the ethylene group is lower than 50 mol %, the resulting
surfactant composition does not show sufficient detergency. Incidentally,
the antifoaming properties of the surfactant composition according to the
present invention can be freely adjusted by changing the proportion of
25 the ethylene group relative to lOO mol % of "A" in the compound (a)
within the above range.
The number (n) of an AO group in the compound (a) is 5 - 50.
When the number (n) of the AO group is less than 5, sufficient
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;~0~4085
detergency cannot be obtained. On the other hand, when n exceeds SO,
detergency also becomes insufficient.
Thus, for instance, when n = 5, "A" is completely composed of
an eth~lene group. And when n is 6 or more, a portion exceeding 5 may
5 be a group other than the ethylene group. In this case, the ethylene
group should be 50 mol % or more based on the total "A."
Incidentally, as long as the content of an oxyethylene group
meets the above requirement, the AO group may be contained in the
compound (a) in the form of random addition, block addition or a mixture
10 of block addition and random addition.
The compound (b) used in the present invention is
represented by the following general formula:
O
2 11
1 5 (R )x P(O(EO)n)y H, ,- (2)
wherein R2 is a substituted or unsubstituted hydrocarbon group having 6
or more carbon atoms, E is an ethylene group, n is an integer of 1 - 20, x
and y are 1 or 2, and x + y = 3.
In the above general formula (2), R2 is a hydrocarbon group
20 having 6 or more carbon atoms. When the number of carbon atoms is 5
or less, good detergency canno~ be obtained.
The mole number (n) of an oxyethylene group represented by
EO is 1 - 20. When there is no oxyethylene group or when the
oxyethylene group exceeds 20 mol, sufficient detergency cannot be
2 5 obtained.
Incidentally, Rl and R2 in the compound (a) and the
compound (b) used in the present invention may be the same or different
from each other, and as long as they are hydrocarbon groups having 6 or
- 6 -
Z0~4085
more carbon atoms, they may be substituted or unsubstituted. Typical
examples of Rl and R2 are alkyl groups such as a hexyl group, an octyl
group, a decyl group, a dodecyl group, a stearyl group; alkenyl groups
such as an oleyl group; cycloalkyl groups such as a cyclohexyl group;
S alkyl-substituted or phenyl-substituted phenyl groups such as a xylene
group, an octyl phenyl group, a nonyl phenyl group, a dodecyl phenyl
group, a dinonyl phenyl group, a paracumyl phenyl group, a styrene-
added phenyl group; an unsubstituted phenyl group, etc.
In the surfactant composition of the present invention, the
10 compound (a) and the compound (b) may be used in combination.
With respect to the weight ratio of the compound (a) to the
compound (b) in the surfactant composition of the present invention,
compound (a)/compound (b) is 10/90 - 95/5, preferably 25/75 - 75/25.
When the weight ratio of the compound (a) to the compound (b) is lower
15 than 10/90 or larger than 95/5, sufficient detergency cannot be obtained.
Next, the degreasing composition of the present invention will
be described below.
The degreasing composition of the present invention
comprises the above surfactant composition containing the compound (a)
20 and the compound (b) in a weight ratio of compound (a)/compound (b) -
10/90 - 95/5 and an alkali builder.
The alkali builders which may be used in the present
invention include alkali metal salts, alkali phosphate, alkali carbonates,
alkali silicates, alkali nitrites, alkali borates, etc., and they may be used
2 5 alone or in combination.
In the degreasing composition of the present invention, a
proportion of the alkali builder to the surfactant composition [wei~ht
ratio of (compound (a) + compound (b))/alkali builder] is 1:0.1 - 1:2000,
- 7 -
2~
preferably 1:1 - 1:100.
When the weight ratio of [(compound (a) + compound
(b))/alkali builder] is less than 1:0.1, the decrease in detergency does not
substantially take place, but it is dif~lcult to maintain a pH for
suppressing the corrosion of metal members to be treated. On the other
hand, when the weight ratio exceeds 1:2000, the concentration of the
surfactant composition in the degreasing detergent ccomposition becomes
too low, resulting in insufficient detergency.
Incidentally, depending upon degreasing facilities, the
degreasing composition of the present invention may further contain 5-
100 parts by weight of an antifoaming agent per 100 parts by weight of
the surfactant composition. When the amount of the antifoaming agent is
less than 5 parts by weight, sufficient improvement of antifoaming
properties cannot be obtained, and when it exceeds 100 parts by weight,
the detergency of the degreasing composition decreases.
The antifoaming agents include higher alcohols, higher ethers,
higher aliphatic acids, higher aliphatic acid esters, and alkyl alkylates or
alkyl phenol alkylates having HLB values of 10 or less, polypropylene
glycolsJpolyethylene glycol ethers, etc. having cloud points of 40C or
lower, and they may be used alone or in combination.
Next, the degreasing bath of the present invention will be
described.
The degreasing bath of the present invention contains the
above surfactant composition and the alkali builder.
The amount of the surfactant composition is 0.005 - 0.5
weight %, preferably 0.05 - 0.3 weight %. When the amount of the
surfactant composition is lower than 0.005 weight %, sufficient
degreasing activity cannot be obtained. When it exceeds 0.5 weight %,
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~ 0~4085
further increase in degreasing activity cannot be achieved.
The amount of the alkali builder is 0.05 - 10 w~ight %,
preferably 1 - 5 weight %. When the amount of the alkali builder is less
than 0.05 weight %, the degreasing detergent solution has a low pH,
5 making it likely that the metal members to be treated are rusted, and
making it difficult to emulsify oil materials removed from the metal
members being treated. On the other hand, when the amount of the
alkali builder exceeds 10 weight %, it is difficult to dissolve the alkali
builder, deteriorating operability.
The composition of the degreasing bath of the present
invention can be adjusted by introducing the surfactant composition and
the alkali builder separately into a degreasing bath (hereinaft~r called
"separate system") or by mixing them in advance and then introducing
the resulting mixture into the degreasing bath (hereinafter called
1 5 "premixed system").
As far as the operability is concerned, the premixed system is
preferable, but from the viewpoint of stability with time, the separa~e
system is preferable. In the case of the premixed system, the amount of
the alkali builder is preferably 80 weight % or more based on the
2 0 surfactant composition to avoid swelling.
As described above, the surfactant composition of the present
invention comprises the compound (a) which is a particular
polyoxyalkylene ether-type nonionic surfactant, and the compound (b)
which is a phosphate-ethylene oxide adduct in a particular proportion.
25 The compound (a) itself does not have sufficient detergency at room
temperature, and the compound (b) itself does not have detergency at all.
Nevertheless, a combination of the compound (a) and the compound (b)
provides a degreasing detergent with good detergency. The reason
g
20~408~;
therefor is not necessarily clear, but it may be considered that a
synergistic effect between the compound (a) and the compound (b)
serves to increase the detergency of the compound (a), while providing
the degreasing detergent with good antifoaming properties.
Further, the degreasing bath of the present invention utilizing
the synergistic effect of the compound (a) and the compound (b) can
maintain degreasing detergency and antifoaming properties equally at
start and even after oil accumulation in the bath.
The present invention will be described in further detail by
means of the following Examples.
SYnthesis of Compound (a)
As the compound (a), the following compounds Al - A9 are
synthesized by adding alkylene oxides to various alcohols and phenols
having various Rl groups in the general formula (1), in the presence of an
alkali catalyst by a usual method.
Al: 7.5 mol of ethylene oxide added to lauryl alcohol.
A2: 10 mol of ethylene oxide added to lauryl alcohol.
A3: 20 mol of ethylene oxide added to lauryl alcohol.
A4: 8 mol of ethylene oxide added to octyl alcohol.
A5: 10 mol of ethylene oxide added to nonyl phenol.
A6: 15 mol of ethylene oxide added to styrene-added phenol.
A7: 10 mol of ethylene oxide block and 3 mol of propylene oxide
block added to nonyl phenol.
A8: 10 mol of ethylene oxide and 7 mol of propylene oxide added
to nonyl phenol in random.
A9: 10 mol of ethylene oxide block and 2 mol of propylene oxide
block added to nonyl phenol.
Svnthesis of Com~ound (b)
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201A0~3S
As the compound (b), the following compounds B1 - B6 are
synthesized by preparing phophates of various alcohols and phenols
having R2 groups in the fomula (2) using phosphorus pentoxide by a
usual method, and then adding ethylene oxide thereto in the presence of
5 an alkali catalyst by a usual method.
B 1: 3 mol of ethylene oxide added to lauryl alcohol phosphate.
B2: 5 mol of ethylene oxide added to lauryl alcohol phosphate.
B3: 12 mol of ethylene oxide added to lauryl alcohol phosphate.
B4: 5 mol of ethylene oxide added to octyl alcohol phosphate.
o B5: 10 mol of ethylene oxide added to nonyl phenol phosphate.
B6: 9 mol of ethylene oxide added to paracumyl phenol
phosphate.
Svnthesis of Compound (c~
For comparison with the compound (b), the following
compound C1 is synthesized by adding 10 mol of ethylene oxide to 1 mol
of nonyl phenyl having an R2 group in the general formula (2) in the
presence of an alkali catalyst by a usual method, and preparing a
phosphate thereof by using phosphorus pentoxide by a usual method.
C1: Phosphate of a nonyl phenol -10 mol ethylene oxide adduct.
Examples_1 - 17. Comparative Examples 1 - 16
Each of surfactant compositions containing the above
compounds A1 - A9, B1 - B6 and C1 as shown in Table 1 is mixed with an
alkali builder in a proportion shown in Table 2 to prepare each
degreasing composition.
2 parts by weight of each degreasing composition is mixed
with 98 parts by weight of water to prepare each degreasing detergent
solution bath.
Evaluation of Deter~encv
- 11 -
8S
With respect to each degreasing detergent solution,
detergency is evaluated at start (fresh composition) and after oil
accumulation in the bath.
(l! Deter~ency at Start
Each degreasing detergent solution is introduced into a 50.0
ml-beaker and kept at 15C. A steel test piece (JIS G-3141) is immersed
in the solution, and the solution is stirred at 200 rpm for 10 minutes.
Thereafter, the steel test piece is removed and rinsed by running water
for 30 seconds to measure water wettability of the steel test piece
surface. This is regarded as detergency at start. Incidentally, the
detergency is regarded as 100% when the entire surface of the steel test
piece is still wet with water 30 seconds after the removal from the bath,
and the water wettability is expressed by percentage of surface area wet
with water observed by the naked eye.
(2! Deter~encv after 0i2 Accumulation
With respect to the above degreasing composition mixed with
2000 ppm of an anti-corrosion oil ("Anti-rust P1400," manufactured by
Nippon Oil Co., Ltd.), a water wettability is measured on the steel test
piece surface in the same method as in the detergency at start, and it is
2 0 evaluated as detergency after oil accumulation.
The evaluation results of each detergency are shown in Table
1.
2s
- 12 -
2~)~14~35
Table 1
Detergencv (%)
Composition of
E,xample Surfactant After Oil
_ No. (Weight Ratio)At StartAccumulation
1 Al/B5 = 75/25 1 00 1 00
2 Al/B5 = 50/50 100 100
3 Al/B5 = 25/75 9 5 9 0
4 A2/B5 = 50/50 1 00 1 00
A3/B5 = 50/50 9 0 8 5
1 0 6 ~4/B5 = 50/50 9 0 8 0
7 A5/B5 = 50/50 1 00 9 0
8 A6/B5 = 50/50 9 0 9 0
9 A7/B5 = 50l50 1 0 0 9 5
1 0 A8/B5 = 50/50 9 5 9 0
1 5 1 1 A9/B5 = 50t50 9 5 9 0
1 2 Al/Bl = 50/50 90 90
1 3 Al/B2 = 50/50 1 00 1 00
1 4 Al/B3 = 50/50 9 5 9 0
1 5 Al/B4 = 50/50 9 5 9 0
2 0 1 6 Al/B5 = 50/50 9 0 8 0
1 7 Al/B6 - 50/50 9 5 9 0
- 13 -
20~40~35
Table 1 (Continued) .
Deter~encv (%3
Comparative Composition of
~xample Surfactant After Oil
No. (Weight Ratio~At StartAccumulation
1 Only Al 50 0
2 Only A2 70 20
3 Only A3 40 0
4 Only A4 30 0
Only A5 75 20
6 Only A6 30 0
7 Only A7 60 0
8 Only A8 40 0
9 Only A9 0 0
Only Bl 0 0
1 1 Only B2 0 0
12 On1y B3 0 0
13 Only B4 0 0
14 Only B5 0 0
Only Cl 10 0
2 0 1 6 Al/Cl = 50/50 5 0 0
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2014085
Table 2
Composition Parts bY Wei~ht
Surfactant Composition 10
Alkali Builder
Sodium Metasilicate SH20 45
Anhydrous Sodium 18
Carbonate
Sodium Phosphate 18
Sodium ~itrite 9
~ .
~ 25:
- 15 -
As is clear from Table 1, the degreasing composition of
the present invention are much better than those of Comparative
Examples I - 16 both at start and after oil accumulation.
;~amples 18 - 21. Comparative Examples 17 - 19
5 l~valuation of ~ntifoamin~ Properties
Various compounds (a) and compounds (b) are mixed in
proportions shown in Table 3 to prepare surfactant compositions,
and each surfactant composition is mixed with an alkali builder in a
proportion shown in Table 2 to prepare a degreasing composition.
10 Next, 2 parts by weight of each degreasing composition is mixed
with 98 parts by weight of water to prepare a degreasing detergent
solution.
The evaluation of antifoaming properties is conducted
on the resulting degreasing detergent solution by a Ross-Miles Test
15 Method. Specifically, 200 ml of the degreasing composition solution
is dropped from a height of 90 cm onto a 50 ml of degreasing
composition solution contained in a glass cylinder of 50 mm in inner
diameter at 25C for 30 seconds to measure the height (mm) of a
foam generated immediately after dropping and the height (mm) 5
20 minutes after dropping. The height of a foam is expressed as a
level of foaming.
The evaluation results of antifoaming properties are
shown in Table 3.
- 16 -
20~4085
Table 3
Foamin g Level (mm~
Composition of Immediately 5 Minutes
Surfactant After After
No._ (Wei,~ht Ratio) Foaming Foamin~
Example
1 8 A1/B1 = 50/50 5 0 3 5
19 A1/B2 = 50/50 6 0 4 3
2 0 A2/B 1 = 50/50 6 5 5 0
2 1 A5/B 1 = 50/50 6 8 4 4
Comparative Example
17 Only A-1 120 75
1 8 Only A-2 140 117
19 Only A-5 13 3 104
20140~5
As is clear from Table 3, the degreasing composition
solution of the present invention is more excellent in antifoaming
properties than those containing conventional surfactants in
Compartive Examples 17-19.
Examples 22. 23, Com~arative Examp~es 20 and 21
AS and Bl are selected as the compound (a) and the
compound (b), and mixed in a weight ratio of 50/S0 to prepare a
surfactant composition, and the surfactant composition is mixed with
an alkali builder in the proportion shown in Table 4 to prepare a
degreasing composition. Next, each degreasing composition is mixed
with water in a proportion shown in Table 4 to prepare a degreasing
composition solution. The resulting degreasing composition solution is
evaluated with respect to detergency and antifoaming properties in
the same method as above. The evaluation results are shown in Table
lS 4.
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2~:14085
Table 4
Comparative
Example No. Example No.
22 23 20 21
5 Composition of
Degreasing Detergent Solution
(Parts bv Weight~
Surfactant (X) 2 2 0.04
Alkali 2 2 0 0 1 0 0 0 . 1
Builder (Y)
Water (Z) 980 1798 900 980
X/Y 1/1 1/100 1/2500 1/0.1
~X/(X+Y+Z)] x 1000.2 0.1 0.004 0.1
(weight %)
1 5 [Y/(X+Y+Z)] x 1000.2 1 0 1 0 0.01
(weight %)
Deter~ency (%)
At Start 100 100 1 0 lO0*
After Oil 95 100 0 70*
2 0 Accumulation
Foamin~ Level (mm~
Immediately7 0 6 7 5
After Foaming
5 Minutes 4 0 4 2 2
2 5 After Foaming
Note *: Steel test piece was rusted.
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~)14085
As is clear from ~able 4, the degreasing composition
solutions in Examples 22 and 23 are much better in detergency than
that of Comparative Example 20 in which the proportion of the
surfactant composition to the alkali builder is less in detergency than
5 l/2G00~ In addition, in Comparative Example 22, in which the content
of the alkali builder in the degreasing composition solution is less than
0.05 weight %, the steel test piece is rusted in the evaluation process
of detergency. Therefore, a proper amount of the alkali builder is
important to adjust pH, thereby achieving the object of the present
1 0 invention.
As described above in detail, since the surfactant
composition of the present invention contains the compound (a) and
the compound (b) in a weight ratio [compound (a)/compound (b)] of
lO/90 - 95/5, the degreasing composition and degreasing
lS bathcontaining such surfactant composition and an alkali builder are
excellent in detergency and antifoaming properties at room
temperature .
The degreasing detergent of the present invention can
advantageously maintain detergency and antifoaming properties even
20 after oil accumulation in the bath on an equal level to that at start.
- 20 -
