U.S. patent application number 17/042240 was filed with the patent office on 2021-04-22 for cleaning of foundry molds.
The applicant listed for this patent is BASF SE. Invention is credited to Michael Koch, Thomas Paasche, Tobias Urban, Henning Urch.
Application Number | 20210114090 17/042240 |
Document ID | / |
Family ID | 1000005326199 |
Filed Date | 2021-04-22 |
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United States Patent
Application |
20210114090 |
Kind Code |
A1 |
Urban; Tobias ; et
al. |
April 22, 2021 |
CLEANING OF FOUNDRY MOLDS
Abstract
The present invention relates to a method of disintegrating a
foundry mold comprising sand and a polyurethane binder. The present
invention further relates to a method of disintegrating a foundry
mold by contacting it with a composition comprising at least one
carboxylic acid amide and at least one tyalkanolamine.
Inventors: |
Urban; Tobias;
(Ludwigshafen, DE) ; Urch; Henning; (Limburgerhof,
DE) ; Koch; Michael; (Ludwigshafen, DE) ;
Paasche; Thomas; (Ludwigshafen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BASF SE |
Ludwigshafen |
|
DE |
|
|
Family ID: |
1000005326199 |
Appl. No.: |
17/042240 |
Filed: |
March 21, 2019 |
PCT Filed: |
March 21, 2019 |
PCT NO: |
PCT/EP2019/057042 |
371 Date: |
September 28, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B22C 1/2273 20130101;
B22D 29/002 20130101; B22D 31/002 20130101; B22C 5/08 20130101 |
International
Class: |
B22D 29/00 20060101
B22D029/00; B22C 1/22 20060101 B22C001/22; B22D 31/00 20060101
B22D031/00; B22C 5/08 20060101 B22C005/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2018 |
EP |
18165295.9 |
Claims
1. A method for disintegrating a foundry mold comprising sand and a
polyurethane based binder comprising (i) contacting the foundry
mold with a composition comprising (a) at least one carboxylic acid
amide of general formula (I) ##STR00028## wherein R.sub.1 denotes
linear or branched, unsubstituted or hydroxy substituted
C.sub.2-C.sub.22 alkyl R.sub.2 and R.sub.3 independently of each
other, denote H or linear or branched, unsubstituted or substituted
C.sub.1-C.sub.12 alkyl; and (b) at least one alkanolamine of
general formula (II) ##STR00029## wherein AO is, identical or
different, selected from the group consisting of
CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O, m is 1, 2, 3, 4, 5, 6 or 7, and x,
y independently of one another are 0 or 1; to obtain a mixture of
the sand and the polyurethane binder.
2. The method according to claim 1, wherein the sand is selected
from the group consisting of natural silica sand, clay, green sand,
quartz sand, chromite sand, olivine sand, special sands, and
zirconium sand.
3. The method according to claim 1, wherein the polyurethane based
binder comprises polyurethane, water glass, and at least one resin
that is different from polyurethane.
4. The method according to claim 1, wherein R.sub.1 is selected
from the group comprising of ethyl, n-propyl, n-butyl, n-pentyl,
n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, isooctyl, isopropyl,
isobutyl, isopentyl, isohexyl, isoheptyl, isononyl, isodecyl,
1-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 1-hydroxybutyl,
2-hydroxybutyl, 1-hydroxypentyl, 2-hydroxypentyl, 3-hydroxypentyl,
4-hydroxypentyl, 1-hydroxyhexyl, 2-hydroxyhexyl, 3-hydroxyhexyl,
4-hydroxyhexyl, and 5-hydroxyhexyl.
5. The method according to claim 1, wherein R.sub.2 and R.sub.3 are
methyl.
6. The method according to claim 1, wherein m is 1, 2 or 3.
7. The method according to claim 1, wherein x and y are 0.
8. The method according to claim 1, wherein the at least one
carboxylic acid amide of general formula (I) and the at least one
alkanolamine of general formula (II) are present in a molar ratio
of 5:1 to 1:5.
9. The method according to claim 1, further comprising (ii)
separating the sand from the mixture obtained in step (i).
10. The method according to claim 1, further comprising the step of
(iii) drying the sand obtained in step (ii).
11. The method according to claim 1, wherein the composition
comprises at least one surfactant.
12. The method according to claim 11, wherein the at least one
surfactant is a non-ionic surfactant.
13. The method according to claim 12, wherein the non-ionic
surfactant is selected from the group consisting of
poly(C.sub.2-C.sub.4)alkylene glycol mono-(C.sub.8-C.sub.22)-alkyl
ether, poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated oil, and
alkoxylated alkylamine.
14. A composition comprising (a) 2-hydroxypropanamide; and (b)
monoethanolamine.
15. The composition according to claim 14 for use in disintegrating
a foundry mold.
16. A method for disintegrating a foundry mold comprising sand and
a polyurethane based binder comprising contacting the foundry mold
with a composition of claim 14 to obtain a mixture of the sand and
the polyurethane binder.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of disintegrating
a foundry mold comprising sand and a polyurethane binder. The
present invention further relates to a method of disintegrating a
foundry mold by contacting it with a composition comprising at
least one carboxylic acid amide and at least one alkanolamine.
BACKGROUND OF THE INVENTION
[0002] All foundries produce castings by pouring molten metal into
molds. The most common type of casting process is known as sand
casting. Sand is used in two different ways in metal casting: as a
molding material, which forms the external shape of the cast part,
and as cores, which form internal void spaces in products such as
engine blocks. Since sand grains do not naturally adhere to each
other, binders must be introduced to cause the sand to stick
together and hold its shape during the introduction of the molten
metal into the mold and the cooling of the casting.
[0003] Sand casting involves manufacturing a pattern of the
component to be cast, and packing sand around the pattern to
produce a hollow mold. Molds are typically made in two halves to
facilitate removal of the pattern, and then the molds are assembled
to form a "hollow" that matches the pattern's shape. Cores made of
packed sand with special binders may be inserted into a mold, prior
to assembly, to form interior surfaces for complex shapes. Molten
metal is poured into the mold cavity and allowed to solidify and
cool. The casting is shaken out of the sand mold using vibratory
machines, mechanically cleaned of extraneous metal by cutting or
grinding, and blast cleaned to remove casting sand and other
surface contaminants. The foundry industry generates a number of
by-products, of which the largest volume is a "spent sand" that
consists of sand with residuals of binders. In addition, sand
casting generates residuals from metal melting and pouring, and
molding processes. It is standard foundry practice to reuse molding
and core making sands. Residual sand is routinely screened and
returned to the system for reuse.
[0004] Various methods are employed for cleaning metal cast in sand
molds which entail both mechanical and chemical actions. In the
former category are included abrasive cleaning methods such as sand
blasting. Chemical methods of cleaning which are available to the
industry, however, produce cleaner castings than the foregoing
mechanical procedures. This is effected because a great deal of
trouble is occasioned by the retention of the granular sand on the
casting by reason of the adhesive properties of the decomposition
products of the organic binders. In such instances the adhering
sand particles are immune to removal by abrasive cleaning methods
and they can only be removed by attacking and dissolving the
residual siliceous particles with a chemical reagent. Further, in
case of the sand molds being held by the binders, sand molds can be
disintegrated by treating them with the compositions or chemicals
which dissolve the synthetic binders, and the sand can then be
processed and reused.
[0005] U.S. Pat. No. 2,666,001 discloses the removal of residual
sand from the cast by immersing in a liquid bath comprising a
strongly acidic solution of fluorophosphoric acid followed by
neutralization. Fluorophosphoric acid being highly toxic and
corrosive, it is difficult to implement the process on a large
scale.
[0006] U.S. Pat. No. 2,766,496 discloses a process of cleaning used
foundry sand which comprises the steps of screening the sand in
presence of water to remove oversized adventitious material,
fluidizing the sand with a jet of water and passing it to
relatively quiescent settling zones wherein loose carbonaceous
impurities are floated off. The disadvantage of the process is that
huge volumes of water waste are generated.
[0007] U.S. Pat. No. 4,411,709, discloses removal of resin bonded
sand molds and sand cores and the reconditioning of the sand for
re-use, by heating the resin bonded molding sand and core sand at a
sufficient temperature to be able to pyrolyze the resin binders in
the sand. However, the process leads to generation of carbonaceous
residues which are difficult to remove.
[0008] Therefore, it is an object of the present invention, while
avoiding the abovementioned and further disadvantages, to provide a
method which is acceptable in both technical and economic respects
for reconditioning used (foundry) sand. It is also an object of the
present invention to provide a method for disintegrating the sand
present in the form of a sand mold and/or sand core from a metal
casting in order to reclaim the sand for further use.
SUMMARY OF THE INVENTION
[0009] Surprisingly, it has been found that the objectives could be
achieved by treating the foundry mold with a composition comprising
a carboxylic acid amide and an alkanolamine. The sand which is
obtained by this method can be reused with minimum steps of further
processing.
[0010] Thus, in one aspect, the presently claimed invention is
directed to a method for disintegrating a foundry mold comprising
sand and a polyurethane binder comprising the step of
[0011] (i) contacting the foundry mold with a composition
comprising
[0012] (a) at least one carboxylic acid amide of general formula
(I)
##STR00001##
[0013] wherein
[0014] R.sub.1 denotes linear or branched, unsubstituted or hydroxy
substituted C.sub.2-C.sub.22 alkyl
[0015] R.sub.2 and R.sub.3 independently of each other, denote H or
linear or branched, unsubstituted or substituted C.sub.1--C.sub.12
alkyl; and
[0016] (b) at least one alkanolamine of general formula (II)
##STR00002##
[0017] wherein
[0018] AO is, identical or different, selected from the group
consisting of CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--,
[0019] m is 1, 2, 3, 4, 5, 6 or 7, and
[0020] x, y independently of one another are 0 or 1
[0021] to obtain a mixture of the sand and the polyurethane
binder.
[0022] In another aspect, the presently claimed invention is
directed to a composition comprising
[0023] (a) 2-hydroxypropanamide; and
[0024] (b) monoethanolamine
[0025] In another aspect, the presently claimed invention is
directed to a composition comprising
[0026] (a) at least one carboxylic acid amide of general formula
(I)
##STR00003##
[0027] wherein
[0028] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl
[0029] R.sub.2 and R.sub.3 denote methyl; and
[0030] (b) monoethanolamine.
[0031] In yet another aspect, the presently claimed invention is
directed to the use of the composition comprising
[0032] (a) 2-hydroxypropanamide; and
[0033] (b) monoethanolamine
[0034] for disintegrating the foundry mold.
[0035] In yet another aspect, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0036] (i) contacting the foundry mold with a composition
comprising [0037] (a) 2-hydroxypropanamide; and [0038] (b)
monoethanolamine;
[0039] to obtain a mixture of the sand and the polyurethane
binder.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Before the present compositions and formulations of the
invention are described, it is to be understood that this invention
is not limited to particular compositions and formulations
described, since such compositions and formulation may, of course,
vary. It is also to be understood that the terminology used herein
is not intended to be limiting, since the scope of the present
invention will be limited only by the appended claims.
[0041] If hereinafter a group is defined to comprise at least a
certain number of embodiments, this is meant to also encompass a
group which preferably consists of these embodiments only.
Furthermore, the terms "first", "second", "third" or "(a)", "(b)",
"(c)", "(d)" etc. and the like in the description and in the
claims, are used for distinguishing between similar elements and
not necessarily for describing a sequential or chronological order.
It is to be understood that the terms so used are interchangeable
under appropriate circumstances and that the embodiments of the
invention described herein are capable of operation in other
sequences than described or illustrated herein. In case the terms
"first", "second", "third" or "(A)", "(B)" and " (C)" or "(a)",
"(b)", "(c)", "(d)", "i", "ii" etc. relate to steps of a method or
use or assay there is no time or time interval coherence between
the steps, that is, the steps may be carried out simultaneously or
there may be time intervals of seconds, minutes, hours, days,
weeks, months or even years between such steps, unless otherwise
indicated in the application as set forth herein above or
below.
[0042] In the following passages, different aspects of the
invention are defined in more detail. Each aspect so defined may be
combined with any other aspect or aspects unless clearly indicated
to the contrary. In particular, any feature indicated as being
preferred or advantageous may be combined with any other feature or
features indicated as being preferred or advantageous.
[0043] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
appearances of the phrases "in one embodiment" or "in an
embodiment" or "in another embodiment" in various places throughout
this specification are not necessarily all referring to the same
embodiment, but may. Furthermore, the particular features,
structures or characteristics may be combined in any suitable
manner, as would be apparent to a person skilled in the art from
this disclosure, in one or more embodiments. Furthermore, while
some embodiments described herein include some but not other
features included in other embodiments, combinations of features of
different embodiments are meant to be within the scope of the
invention, and form different embodiments, as would be understood
by those in the art.
[0044] In one aspect, the presently claimed invention relates to a
method for disintegrating the foundry mold comprising sand and a
polyurethane binder comprising the step of
[0045] (i) contacting the foundry mold with a composition
comprising
[0046] (a) at least one carboxylic acid amide of general formula
(I)
##STR00004##
[0047] wherein
[0048] R.sub.1 denotes linear or branched, unsubstituted or hydroxy
substituted C.sub.2-C.sub.22 alkyl
[0049] R.sub.2 and R.sub.3 independently of each other, denote H or
linear or branched, unsubstituted or substituted C.sub.1-C.sub.12
alkyl; and
[0050] (b) at least one alkanolamine of general formula (II)
##STR00005## [0051] wherein [0052] AO is, identical or different,
selected from the group consisting of CH.sub.2--CH.sub.2--O,
CH(CH.sub.3)--CH.sub.2--O, CH.sub.2-CH(CH.sub.3)--O,
CH(C.sub.2H.sub.5)--CH--O, C(CH.sub.3).sub.2--CH.sub.2--O,
CHC(CH.sub.3).sub.2--O and CH.sub.2--CH(C.sub.2H.sub.5)--O [0053] m
is 1, 2, 3, 4, 5, 6 or 7, and [0054] x, y independently of one
another are 0 or 1
[0055] to obtain a mixture of the sand and the polyurethane
binder.
[0056] For the purposes of the presently claimed invention, the
term `disintegrating` includes cleaning of foundry molds of
residual sand and binder which are left on it after the molding
process. Additionally, it also covers the `complete breaking of the
foundry mold` wherein the sand and binder is separated and the sand
can be recycled. Accordingly, a mixture of sand and binder refers
to a mixture in which the sand and the binder are present in form
of discrete materials.
[0057] `Foundry mold` herein refers to molds made of sand and
binder.
[0058] `Contacting` denotes immersing the foundry mold in the
composition. It may also include adding the composition on to a
metal cast. When the foundry mold is immersed in the composition,
it disintegrates into sand and binder. In case when the composition
is added on to a metal cast, it is done to clean the metal cast of
the residual sand and binder mixture, after the process of
casting.
[0059] For the purposes of the presently claimed invention, the
term "C.sub.1-C.sub.12-alkyl" covers acyclic saturated hydrocarbon
residues, which may be linear or branched and unsubstituted or at
least mono-substituted with, as in the case of
C.sub.1-C.sub.12-alkyl, 1 to 12 (i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11 or 12) carbon atoms. Similarly, the term
"C.sub.2-C.sub.22-alkyl" covers acyclic saturated hydrocarbon
residues, which may be linear or branched and unsubstituted or at
least mono-substituted with, as in the case of
C.sub.2-C.sub.32-alkyl, 2 to 22 (i.e. 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 or 22) carbon atoms. If
one or more of the substituents denote an alkyl residue which is
mono- or polysubstituted, this may preferably be substituted with
optionally 1, 2, 3, 4 or 5, particularly preferably with 1, 2 or 3,
substituents mutually independently selected from the group
consisting of F, Cl, Br, I, --NO.sub.2, --CN, --OH, --SH,
--NH.sub.2, --N(C.sub.1-5-alkyl).sub.2,
--N(C.sub.15-alkyl-OH).sub.2, --N(C.sub.1-5-alkyl)(phenyl),
--N(C.sub.15-alkyl)(CH.sub.2-phenyl),
--N(C.sub.1-5-alkyl)(CH.sub.2-CH.sub.2-phenyl), --C(.dbd.O)--H,
--C(.dbd.O)--C.sub.1-5-alkyl, --C(.dbd.O)-phenyl,
--C(.dbd.S)--C.sub.1-5-alkyl, C(.dbd.S)-phenyl, --C(.dbd.O)--OH,
--C(.dbd.O)--O--C.sub.1-5-alkyl, --C(.dbd.O)--O-phenyl,
--C(.dbd.O)--NH.sub.2, --C(.dbd.O)--NH--C.sub.1-5-alkyl,
--C(.dbd.O)--N(C.sub.1-5-alkyl).sub.2,
--S(.dbd.O)--C.sub.1-5-alkyl, --S(.dbd.O)-phenyl,
--S(.dbd.O).sub.2-C.sub.1-5-alkyl, --S(.dbd.O).sub.2-phenyl,
--S(.dbd.O).sub.2--NH.sub.2 and --SO.sub.3H, wherein the
above-stated-C.sub.1-5 alkyl residues may in each case be linear or
branched and the above-stated phenyl residues may preferably be
substituted with 1, 2, 3, 4 or 5 substituents mutually
independently selected from the group consisting of F, CI, Br, I,
--CN, --CF.sub.3, --OH, --NH.sub.2, --O--CF.sub.3, --SH,
--O--CH.sub.3, --O--C.sub.2H.sub.5, --O--C.sub.3H.sub.7, methyl,
ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl and
tert.-butyl. Particularly preferred substituents may be selected
mutually independently from the group consisting of F, Cl, Br, I,
--NO.sub.2, --CN, --OH, --SH, --NH.sub.2, --N(CH.sub.3).sub.2,
--N(C.sub.2H.sub.5).sub.2and --N(CH.sub.3)(C.sub.2H.sub.5). As used
herein, "branched" denotes a chain of atoms with one or more side
chains attached to it. Branching occurs by the replacement of a
substituent, e.g., a hydrogen atom, with a covalently bonded alkyl
radical.
[0060] Carboxylic acid amide of general formula (I)
[0061] The carboxylic acid amide of general formula (I) has the
following structure
##STR00006##
[0062] wherein
[0063] R.sub.1 denotes linear or branched, unsubstituted or hydroxy
substituted C.sub.2-C.sub.22 alkyl
[0064] R.sub.2 and R.sub.3 independently of each other, denote H or
linear or branched, unsubstituted or substituted C.sub.1-C.sub.12
alkyl.
[0065] Preferably, R.sub.1 is selected from the group consisting of
ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl,
n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl,
n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl,
n-eicosyl, n-heneicosyl, n-docosyl, isopropyl, isobutyl, isopentyl,
isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl,
isododecyl, isotridecyl, isotetradecyl, isopentadecyl,
isohexadecyl, isoheptadecyl, isooctadecyl, isononadecyl,
isoeicosyl, isoheneicosyl, isodocosyl, t-butyl, 1-hydroxyethyl,
1-hydroxypropyl, 2-hydroxypropyl, 1-hydroxybutyl, 2-hydroxybutyl,
2-hydroxybutyl, 1-hydroxypentyl, 2-hydroxypentyl, 3-hydroxypentyl,
4-hydroxypentyl, 1-hydroxyhexyl, 2-hydroxyhexyl, 3-hydroxyhexyl,
4-hydroxyhexyl and 5-hydroxyhexyl.
[0066] More preferably, R.sub.1 is selected from the group
consisting of ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl,
n-heptyl, n-octyl, n-nonyl, n-decyl, isooctyl, isononyl, isodecyl,
isopropyl, isobutyl, isopentyl, isohexyl, isoheptyl, isodecyl,
1-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 1-hydroxybutyl,
2-hydroxybutyl, 2-hydroxybutyl, 1-hydroxypentyl, 2-hydroxypentyl,
3-hydroxypentyl, 4-hydroxypentyl, 1-hydroxyhexyl, 2-hydroxyhexyl,
3-hydroxyhexyl, 4-hydroxyhexyl and 5-hydroxyhexyl. Most preferably,
R.sub.1 is selected from the group consisting of n-octyl, n-nonyl,
n-decyl, isooctyl, isononyl, isodecyl and 1-hydroxyethyl.
Particularly preferably, R.sub.1 is 1-hydroxyethyl.
[0067] In an embodiment, R.sub.2 and R.sub.3 independently of each
other, are selected from the group consisting of H, methyl, ethyl,
n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl,
n-decyl, n-undecyl, n-dodecyl, isopropyl, isobutyl, isopentyl,
isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl,
isododecyl and t-butyl.
[0068] In a preferred embodiment, R.sub.2 and R.sub.3 independently
of each other, are selected from the group consisting of H, methyl,
ethyl, n-propyl, n-butyl, isopropyl, isobutyl and t-butyl.
[0069] Most preferably, R.sub.2 and R.sub.3 independently of each
other, are selected from the group consisting of methyl, ethyl and
n-propyl.
[0070] In a particularly preferred embodiment, R.sub.2 and R.sub.3
are methyl.
[0071] Accordingly, in an embodiment the compound of general
formula (I) is 2-hydroxypropanamide.
[0072] Suitable carboxylic acid amides are known and commercially
available under the tradenames Agnique.RTM. AMD 3L, Agnique.RTM.
AMD10 and Agnique.RTM. AMD 810 from BASF SE.
[0073] In a preferred embodiment, the presently claimed invention
relates to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0074] (i) contacting the foundry mold with a composition
comprising [0075] (a) 2-hydroxypropanamide; and [0076] (b) at least
one alkanolamine of general formula (II)
##STR00007##
[0077] wherein
[0078] AO is, identical or different, selected from the group
consisting of CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O,
[0079] m is 1, 2, 3, 4, 5, 6 or 7, and
[0080] x, y independently of one another are 0 or 1;
[0081] to obtain a mixture of the sand and the polyurethane
binder.
[0082] Alkanolamine of general formula (II)
[0083] The alkanolamine of general formula (II) has the following
structure
##STR00008##
[0084] wherein
[0085] AO is, identical or different, selected from the group
consisting of CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O,
[0086] m is 1, 2, 3, 4, 5, 6 or 7, and
[0087] x, y independently of one another are 0 or 1.
[0088] Preferably m is 1, 2 or 3, more preferably m is 2.
[0089] Preferably, x and y are both 0.
[0090] Accordingly, in an embodiment the compound of general
formula (II) is monoethanolamine.
[0091] In a preferred embodiment, the presently claimed invention
relates to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0092] (i) contacting the foundry mold with a composition
comprising [0093] (a) at least one carboxylic acid amide of general
formula (I)
[0093] ##STR00009## [0094] wherein [0095] R.sub.1 denotes linear or
branched, unsubstituted or hydroxy substituted C.sub.2-C.sub.22
alkyl [0096] R.sub.2 and R.sub.3 independently of each other,
denote H or linear or branched, unsubstituted or substituted
C.sub.1-C.sub.12 alkyl; and [0097] (b) monoethanolamine; to obtain
a mixture of the sand and the polyurethane binder.
[0098] Sand
[0099] The sand is selected from the group consisting of natural
silica sand, clay, green sand, quartz sand, chromite sand, olivine
sand, special sands and zirconium sand.
[0100] Silica sand in form of granular quarts is the main
constituent of molding sand having enough refractoriness which can
impart strength, stability and permeability to molding and core
sand. But along with silica small amounts of iron oxide, alumina,
lime stone (CaCO.sub.3), magnesia, soda and potash are present as
impurities. The chemical composition of silica sand gives an idea
of the impurities like lime, magnesia, alkalis etc. present. The
presence of excessive amounts of iron oxide, alkali oxides and lime
can lower the fusion point to a considerable extent which is
undesirable. The silica sand can be specified according to the sand
grain size and the shape (angular, sub-angular and rounded) of the
sand.
[0101] Clay sand is the mixture of natural silica sand, clay,
additives and water. The clay used to make wet clay sand is
bentonite clay. The compressive strength is generally 0.05 to 0.1
MPa. The water content is 3.5 to 5%.
[0102] Green Sand is a mixture of silica sand, chromite sand, or
zircon sand, bentonite (clay), inert sludge, anthracite, sometimes
with a proportion of olivine, staurolite or graphite.
[0103] Quartz sand contains mainly crystalline silica SiO.sub.2 and
additional mineral contents such as feldspars, clay minerals, mica
minerals as well as carbonate and carbonaceous components.
[0104] The suitability of quartz grains as molding material is
mainly determined by the SiO.sub.2 content. The higher the content,
i.e. the fewer additions of low-melting compounds, the more
favorable the sand will behave towards high thermal loads.
[0105] Chromite sand is a naturally occurring spinel consisting
primarily of the oxides of chrome and iron.
[0106] Olivine sand is composed mainly of silica, magnesium oxide,
iron oxide and aluminium oxide. It has a low thermal expansion rate
compared to silica sand.
[0107] Special sands include natural mineral sands, sintering and
melting products produced in granular form or turned into granular
form by breaking, grinding and grading processes, or inorganic
mineral sands produced by other physical-chemical methods. Special
sands are different from quartz sand, particularly due to their
significantly lower thermal expansion behavior within the
temperature range of 20 to 600.degree. C., their heat conductivity,
refractoriness, and other physical characteristics.
[0108] Preferably the sand is silica sand or special sand.
[0109] Polyurethane Based Binders
[0110] The polyurethane based binders are polyurethane based
binders which may also include, in addition to polyurethane,
components such as water glass (sodium silicate) and resins like
phenol formaldehyde, urea formaldehyde and furan resins.
[0111] Polyurethanes are formed from polyhydroxy compounds and
polyisocyanates. The polyhydroxy compounds in turn are commonly
prepared from phenols and formaldehyde. The polyhydroxy component
may be any organic hydroxy compound having a functionality of two
or more that is soluble in the solvents employed. Such polyhydroxy
compounds can include simple aliphatic polyols, amine polyols,
polyether polyols, phenolic resins and mixtures of these.
[0112] The amine polyols are normally produced as the reaction
product of an alkylene oxide and an amine compound. In general, any
polyol containing at least one or more tertiary amine groups is
considered to be within the scope of the definition of "amine
polyol". The amine compounds which react with alkylene oxides to
yield the amine polyols include ammonia and mono- and polyamine
compounds with primary or secondary amino nitrogen. Specific
examples include aliphatic amines such as primary alkyl amines,
ethylene diamine, diethylene triamine and triethylene tetraamine,
cycloaliphatic amines, aromatic amines, such as ortho-, meta-, and
para-phenylene diamines and aniline formaldehyde resins.
[0113] The phenols employed in the formation of such phenolic
resins are generally any of the phenols which may be utilized in
the formation of phenolic resins. Specific suitable phenols which
may be used include phenol, o-cresol, m-cresol, p-cresol, 2,
5-xylenol, 3, 4-xylenol, 3, 5-xylenol, 3, 4, 5-trimethylphenol,
2-ethylphenol, 3-ethylphenol, 3, 5-diethylphenol,
o-sec-butylphenol, p-butylphenol, 3, 5-dibutylphenol, p-amylphenol,
p-cyclohexylphenol, o-octylphenol, o-sec-decylphenol, nonylphenol,
3, 5-dicyclohexylphenol, p-phenylphenol, p-crotylphenol,
2-methoxyphenol, 3, 5-dimethoxyphenol, 3, 4, 5-trimethoxyphenol,
p-ethoxyphenol, 3-methyl-4-methoxyphenol and p-phenoxyphenol.
[0114] The furan resins that are used for foundry binders are
usually prepared from reacting furfuryl alcohol with
urea-formaldehyde resins, or with formaldehyde, in order to obtain
low-viscosity, soluble, fusible, furan resins. In some cases,
phenolic resins or other modifiers are added to the furan
resins.
[0115] The aldehyde employed in the formation of the phenolic and
furan resin component include any of the aldehydes heretofore
employed in the formation of phenolic resins such as formaldehyde,
acetaldehyde, propionaldehyde, furfuraldehyde and benzaldehyde.
[0116] The isocyanate component which can be employed in a binder,
may have a functionality of 2 or more. Exemplary isocyanates are
organic polyisocyanates such as tolylene-2, 4-diisocyanate,
tolylene-2, 6-diisocyanate and mixtures thereof, and particularly
the crude mixtures thereof that are commercially available. Other
typical polyisocyanates include methylene-bis-(4-phenylisocyanate),
n-hexyl diisocyanate, naphthalene-1, 5-diisocyanate,
cyclopentylene-1, 3-diisocyanate, p-phenylene diisocyanate,
tolylene-2, 4, 6-triisocyanate and triphenylmethane-4, 4',
4''-triisocyanate. Higher isocyanates are provided by the liquid
reaction products of (1) diisocyanates and (2) polyols or
polyamines and the like. In addition, isothiocyanates and mixtures
of isocyanates can be employed. Also contemplated are the many
impure or crude polyisocyanates that are commercially available.
The isocyanate component may additionally contain a chlorosilane
compound selected from the group consisting of
trimethylchlorosilane, dimethyldichlorosilane,
methyltrichlorosilane, tetrachlorosilane, diethychlorosilane,
vinyltrichlorosilane and diphenyldichlorosilane.
[0117] Other commonly employed additives can be optionally used in
the binder. The use of such materials may enhance the adhesion of
the binder to the aggregate material. Examples of additives
include, but are not limited to, amino silanes, epoxy silanes,
mercapto silanes, hydroxy silanes and ureido silanes such as, for
example, gamma-aminopropyltrimethoxysilane,
gamma-hydroxypropyltrimethoxysilane, 3-ureidopropyl
triethoxysilane, gamma-mercaptopropyltrimethoxysilane,
gamma-glycidoxypropyltrimethoxysilane, beta-(3,
4-epoxycyclohexyl)trimethoxysilane and N-beta-(aminoethyl
gamma-aminopropyltrimethoxy silane.
[0118] Surfactants
[0119] In an embodiment, the composition that is used according to
the presently claimed invention further comprises at least one
surfactant. The at least one surfactant is selected from the group
consisting of anionic surfactant, cationic surfactant, non-ionic
surfactant and amphoteric surfactant.
[0120] Suitable anionic surfactants are selected from the group
consisting of salt of alkyl sulfate, alkyl ether sulfate, a-olefin
sulfonate and linear alkyl benzene sulfonate.
[0121] The alkyl sulfates are compounds of the formula:
ROSO.sub.3.sup.-M.sup.+
wherein
[0122] R denotes linear or branched, unsubstituted C.sub.6-C.sub.22
alkyl,
[0123] M denotes alkali metal or ammonium cation
[0124] For the purposes of the presently claimed invention, the
term "C.sub.6-C.sub.22-alkyl" covers acyclic saturated hydrocarbon
residues, which may be linear or branched and unsubstituted having
6 to 22 carbon atoms.
[0125] The alkyl sulfates are obtained by sulfating the higher
alcohols (C.sub.6-C.sub.22 carbon atoms) produced from the
glycerides of tallow, coconut oil, suitable vegetable oil or
synthetic alcohols followed by neutralization with alkali
hydroxide. Thus, the alkyl sulfates also contain reaction
by-products such as free salt (for example sodium chloride is the
free salt by product, when neutralization agent is sodium
hydroxide), free fatty alcohol, salt of fatty alcohol. Therefore,
the solid content of the alkyl sulfate will be different from the
active content. Active content denotes the amount of alkyl sulfate'
present in the composition whereas the solid content denotes `a
total of alkyl sulfate, fatty alcohol, salt of fatty alcohol and
the free salt` in the composition. `Free` herein denotes that the
salt is not bound to the fatty alcohol/alkyl sulfate by any kind of
chemical bonding.
[0126] Alkyl ether sulfates are compounds of the formula
R'--O--(C.sub.2H.sub.4O).sub.n--SO.sub.3M
[0127] wherein
[0128] R' denotes linear or branched, unsubstituted C.sub.6C.sub.22
alkyl,
[0129] n is from 1 to 20
[0130] M denotes alkali metal or ammonium cation
[0131] The alkyl ether sulfates are produced by the ethoxylation of
fatty alcohol and thus will generally be obtained in the form of
mixtures comprising varying alkyl chain lengths and varying degrees
of ethoxylation. Frequently such mixtures will inevitably also
contain some non-ethoxylated alkyl sulfates.
[0132] .alpha.-olefin sulfonates are generally produced by
sulfonating .alpha.-olefin. The .alpha.-olefins, which are
sulfonated to form the surfactants used in the compositions of the
present invention, may contain from about 10 to 22 carbon atoms and
preferably 12 to 18 carbon atoms. They may be derived from a
variety of processes such as, for example, by wax cracking,
ethylene build up or dehydration of the corresponding primary
alcohol. Exemplary alpha-olefins are 1-decene, 1-undecene,
1-dodccene, 1-tridecene, 1-tetradecene, 1-pentadecene,
1-hexadecene, 1-heptadecene, 1-octadecene and the like and mixtures
of the aforesaid. Sulfonation of these long chain olefins is
typically carried out utilizing sulfur trioxide mixed with a
diluent. After the sulfonation is completed, neutralization and
hydrolysis of the acid mixture is carried out so that any
by-product sultones which are formed are converted to the
corresponding hydroxyalkane sulfonates. Thus, as is well known in
the art, the term .alpha.-olefin sulfonates as used herein includes
not only the alkene sulfonate itself but also admixtures of same
formed as a result of the usual sulfonation neutralization, and
hydrolysis procedure with substantial proportions of the
corresponding water soluble hydroxyalkane sulfonates.
[0133] Linear alkyl benzene sulfonate (LABS) is produced by
sulfonation of linear alkylbenzene (LAB) and subsequent
neutralization of the corresponding sulfonic acid (HLAS). Linear
alkylbenzene is synthesized by the alkylation of benzene with
linear olefins. Traditional processes for alkylation of aromatics
compounds use Friedel-Craft type catalysts, for example,
hydrofluoric acid, aluminum trichloride and the like.
[0134] Anionic surfactant may also include alkylamide sulphates of
formula
R.sub.4CONHR.sub.5OSO.sub.3M
wherein
[0135] R.sub.4 denotes a C.sub.2-C.sub.22 alkyl
[0136] R.sub.5 C.sub.2-C.sub.3 alkyl radical,
[0137] M is a hydrogen atom or an alkali metal cation cation or
ethoxylenated (EO) and/or propoxylenated (PO) derivatives thereof,
containing on average from 0.5 to 60 EO and/or PO units;
[0138] Further anionic surfactants are, salts of C.sub.8-C.sub.24,
saturated or unsaturated fatty acids, alkylglyceryl sulphonates,
paraffin sulphonates, N-acyl N-alkyltaurates, alkylphosphates,
isethionates, alkylsuccinamates, alkylsulphosuccinates,
sulphosuccinate monoesters or diesters, N-acyl sarcosinates,
alkylglycoside sulphates, polyethoxycarboxylates, the cation being
an alkali metal (sodium, potassium or lithium), a substituted or
unsubstituted ammonium residue (methyl-, dimethyl-, trimethyl- or
tetramethylammonium, dimethylpiperidinium, etc.) or an alkanolamine
derivative (monoethanolamine, diethanolamine, triethanolamine,
etc.) and alkyl or alkylaryl phosphate esters.
[0139] Cationic surfactants are a well-known group of
surface-active compounds which have at least one active cationic
(positive ion) constituent. As the cationic surfactant, quaternary
ammonium hydroxides such as octyltrimethylammonium hydroxide,
dodecyltrimethylammonium hydroxide, hexadecyltrimethylammonium
hydroxide, octyldimethylbenzylammonium hydroxide
decyldimethylbenzylammonium hydroxide, didodecyldimethylammonium
hydroxide, dioctadecyldimethylammonium hydroxide, beef tallow
trimethylammonium hydroxide, and coconut oil trimethylammonium
hydroxide, and their salts can be exemplified.
[0140] Examples of amphoteric surfactants comprise betaines,
sulphobetaines and carboxylates and sulphonates of fatty acids and
of imidazole, such as alkyldimethylbetaines,
alkylamidopropyldimethylbetaines, alkyldimethylsulphobetaines or
alkylamidopropyldimethylsulphobetaines, such as Mirataine CBS sold
by the company Rhodia, and the products of condensation of fatty
acids and of protein hydrolysates; alkylamphoacetates or
alkylamphodiacetates in which the alkyl group contains from 6 to 20
carbon atoms; amphoteric alkylpolyamine derivatives such as
Amphionic XL.RTM. sold by Rhodia and Ampholac 71/X.RTM. and
Ampholac 7C/X.RTM. sold by Berol Nobel.
[0141] The at least one surfactant is preferably a non-ionic
surfactant.
[0142] The at least one non-ionic surfactant is selected from the
group consisting of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated
oil and alkoxylated alkylamine.
[0143] The poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether is preferably
poly(C.sub.2-C.sub.3)alkylene glycol mono-(C.sub.8-C.sub.22)-alkyl
ether.
[0144] Preferred poly(C.sub.2-C.sub.3)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether are preferably compounds of the
formula
R.sub.6--(O--CH.sub.2-CH.sub.2),(O--CH(CH.sub.3)--CH.sub.2).sub.r--OH
wherein
[0145] R.sub.6 is linear or branched C.sub.8-C.sub.22-alkyl;
[0146] q is a natural number from 1 to 50; and
[0147] r is 0 or is a natural number from 1 to 30, with the proviso
that 2.ltoreq.q+r.ltoreq.50.
[0148] In a preferred embodiment, the poly(C.sub.2-C.sub.3)alkylene
glycol mono-(C.sub.8-C.sub.22)-alkyl ether are preferably compounds
of the formula
R.sub.6--(O--CH.sub.2-CH.sub.2).sub.q(O--CH(CH.sub.3)--CH.sub.2).sub.r---
OH
wherein
[0149] R.sub.6 is linear or branched C.sub.8-C.sub.22-alkyl;
[0150] q is a natural number from 1 to 15; and
[0151] r is 0 or is a natural number from 1 to 20, with the proviso
that 2.ltoreq.q+r.ltoreq.30.
[0152] Within the context of the present invention, the term
"alkyl", as used herein, refers to acyclic saturated aliphatic
residues, including linear or branched alkyl residues. Furthermore,
the alkyl residue is unsubstituted and includes as in the case of
C.sub.8-C.sub.22 alkyl 8 to 22 carbon atoms.
[0153] Representative examples of linear and branched
C.sub.8-C.sub.22 alkyl include, but are not limited to, n-octyl,
n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl,
n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl,
n-eicosyl, n-heneicosyl, n-docosyl, 2-ethylhexyl, 2-propyl-heptyl,
2-butyl-1-octyl, 2-pentyl-1-nonyl, isooctyl, isodecyl, isoundecyl,
isododecyl, isotridecyl, isotetradecyl, isopentadecyl,
isohexadecyl, isoheptadecyl, isooctadecyl, isononadecyl,
isoeicosyl, isoheneicosyl, and isodocosyl.
[0154] The poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether have a molecular weight of from
300 g/mol to 2000 g/mol determined by .sup.1H-NMR spectroscopy
using for instance a 400 MHz spectrometer by Bruker. The molecular
weight can be determined by the integration of the signals of the
poly(C.sub.2--C.sub.4)alkylene glycol backbone and the comparison
of this integral with the integral of the
mono-(C.sub.8--C.sub.22)-alkyl signals.
[0155] The poly(C.sub.2--C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether can be prepared by alkoxylation
of fatty alcohol. When the fatty alcohol R.sup.1--OH which is used
for the synthesis of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether is derived from a natural
source it is common to have mixtures, e.g. of C.sub.16 and C.sub.18
alcohols or C.sub.12 and C.sub.14 alcohols. Fatty alcohol
R.sup.1--OH can also be synthesized (for example by oxo process)
from olefin mixtures and in this case, it is common to have
mixtures e.g. of C.sub.13 and C.sub.15 alcohols.
[0156] Suitable poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether are known and commercially
available, e.g. Lutensol.RTM. XL from BASF SE.
[0157] The poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-carboxylic acid ester are preferably
compounds of the formula
R.sub.6--CO--(O--CH.sub.2--CH.sub.2).sub.q(O--CH(CH.sub.3)--CH.sub.2).su-
b.r--R.sub.7
wherein
[0158] R.sub.6 is linear or branched C.sub.8-C.sub.22-alkyl;
[0159] R.sub.7 is H or linear or branched C.sub.1-C.sub.8
alkyl;
[0160] q is a natural number from 1 to 50; and
[0161] r is 0 or is a natural number from 1 to 30, with the proviso
that 2.ltoreq.q+r.ltoreq.50
[0162] Representative examples of linear or branched
C.sub.8-C.sub.22 alkyl include, but are not limited to, n-octyl,
n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl,
n-pentadecyl, n-hexa-decyl, n-heptadecyl, n-octadecyl, n-nonadecyl,
n-eicosyl, n-heneicosyl, n-docosyl, 2-ethylhexyl, 2-propyl-heptyl,
2-butyl-1-octyl, 2-pentyl-1-nonyl, isooctyl, isodecyl, isoundecyl,
isododecyl, isotridecyl, isotetradecyl, isopentadecyl,
isohexadecyl, isoheptadecyl, isooctadecyl, isononadecyl,
isoeicosyl, isoheneicosyl, isodocosyl and isomers thereof.
[0163] Representative examples of linear or branched
C.sub.1-C.sub.8 alkyl include, but are not limited to, methyl,
ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl,
isopropyl, isobutyl, isopentyl, isohexyl, isoheptyl, isooctyl,
t-butyl, 2-ethylhexyl and isomers thereof.
[0164] The poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-carboxylic acid esters have a molecular
weight of from 300 to 2000 determined by .sup.1H-NMR spectroscopy
using for instance a 400 MHz spectrometer by Bruker. The molecular
weight can be determined by the integration of the signals of the
poly(C.sub.2-C.sub.4)alkylene glycol backbone and the comparison of
this integral with the integral of the
mono-(C.sub.8-C.sub.22)-alkyl signals.
[0165] The alkoxylated oil is preferably an ethoxylated oil, more
preferably ethoxylated derivative of castor oil with a
hydrophilic/lipophilic balance of about 14 (HLB 14), such as
Emulan.RTM. EL.
[0166] The alkoxylated alkylamine are preferably compounds of the
formula
##STR00010##
wherein
[0167] R is linear or branched, substituted or unsubstituted
C.sub.8-C.sub.22-alkyl or linear or branched, substituted or
unsubstituted C.sub.8-C.sub.22-alkenyl;
[0168] AO is, identical or different, selected from the group
consisting of CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O,
[0169] a is a natural number from 1 to 20; and
[0170] b is a natural number from 1 to 20, with the proviso that
2.ltoreq.a+b.ltoreq.40.
[0171] For the purpose of the presently claimed invention, the term
"alkenyl" covers acyclic unsaturated hydrocarbon residues, which
may be linear or branched and unsubstituted or at least
mono-substituted and comprise at least one double bond, preferably
1, 2 or 3 double bonds, with, as in the case of C.sub.8-C.sub.22
alkenyl, 8 to 22 (i.e. 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 21, 22) carbon atoms. If one or more of the substituents
denote an alkenyl residue which is mono- or polysubstituted, this
may preferably be substituted with optionally 1, 2, 3, 4 or 5,
particularly preferably with 1, 2 or 3, substituents mutually
independently selected from the group consisting of F, Cl, Br, I,
--NO.sub.2, --CN, --OH, --SH, --NH.sub.2,
--N(C.sub.1-5-alkyl).sub.2, --N(C.sub.15-alkyl-OH).sub.2,
--N(C.sub.1-5-alkyl)(phenyl), --N(C.sub.15-alkyl)(CH.sub.2-phenyl),
--N(C.sub.1-5-alkyl)(CH.sub.2-CH.sub.2-phenyl), --C(.dbd.O)--H,
--C(.dbd.O)--C.sub.1-5-alkyl, --C(.dbd.O)-phenyl,
--C(.dbd.S)--C.sub.1-5-alkyl, C(.dbd.S)-phenyl, --C(.dbd.O)--OH,
--C(.dbd.O)--O--C.sub.1-5-alkyl, --C(.dbd.O)--O-phenyl,
--C(.dbd.O)--NH.sub.2, --C(.dbd.O)--NH--C.sub.1-5-alkyl,
--C(.dbd.O)--N(C.sub.1-5-alkyl).sub.2,
--S(.dbd.O)--C.sub.1-5-alkyl, --S(.dbd.O)-phenyl,
--S(.dbd.O).sub.2-C.sub.1-5-alkyl, --S(.dbd.O).sub.2-phenyl,
--S(.dbd.O).sub.2--NH.sub.2 and --SO.sub.3H, wherein the
above-stated-C.sub.1-5 alkyl residues may in each case be linear or
branched and the above-stated phenyl residues may preferably be
substituted with 1, 2, 3, 4 or 5 substituents mutually
independently selected from the group consisting of F, Cl, Br, I,
--CN, --CF.sub.3, --OH, --NH.sub.2, --O--CH.sub.3--SH,
--O--CH.sub.3, --O--C.sub.2H.sub.5, --O--C.sub.3H.sub.7, methyl,
ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl and
tert-butyl. Particularly preferred substituents may be selected
mutually independently from the group consisting of F, Cl, Br, I,
--NO.sub.2, --CN, --OH, --SH, --NH.sub.2, --N(CH.sub.3).sub.2,
--N(C.sub.2H.sub.5).sub.2and --N(CH.sub.3)(C.sub.2H.sub.5).
[0172] Preferably, R is linear, unsubstituted
C.sub.8-C.sub.22-alkenyl; AO is CH.sub.2--CH.sub.2--O, a is a
natural number from 1 to 10; b is a natural number from 1 to 10,
with the proviso that 5.ltoreq.a+b.ltoreq.20.
[0173] More preferably, alkoxylated alkylamine is an ethoxylated
alkylamine and most preferably oleyl amine ethoxylate. Suitable
alkoxylated alkylamine are known and commercially available, e.g.
Lutensol.RTM. FA12 from BASF SE.
[0174] Particularly preferably, the non-ionic surfactant is
selected from alkyl polyethylene glycol ether, ethoxylated castor
oil and oleyl amine ethoxylate.
[0175] In a preferred embodiment the presently claimed invention
relates to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0176] (i) contacting the foundry mold with a composition
comprising [0177] (a) at least one carboxylic acid amide of general
formula (I)
[0177] ##STR00011## [0178] wherein [0179] R.sub.1 denotes linear or
branched, unsubstituted or hydroxy substituted C.sub.2--C.sub.22
alkyl [0180] R.sub.2 and R.sub.3 independently of each other,
denote H or linear or branched, unsubstituted or substituted
C.sub.1-C.sub.12 alkyl; [0181] (b) at least one alkanolamine of
general formula (II)
[0181] ##STR00012## [0182] wherein [0183] AO is, identical or
different, selected from the group consisting of
CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O, [0184] m is 1, 2, 3, 4, 5, 6 or 7,
and [0185] x, y independently of one another are 0 or 1; and [0186]
(c) at least one non-ionic surfactant;
[0187] to obtain a mixture of the sand and the polyurethane
binder.
[0188] In another preferred embodiment the presently claimed
invention relates to a method for disintegrating the foundry mold
comprising sand and a polyurethane binder comprising the step
of
[0189] (i) contacting the foundry mold with a composition
comprising
[0190] (a) at least one carboxylic acid amide of general formula
(I)
##STR00013##
[0191] wherein
[0192] R.sub.1 denotes linear or branched, unsubstituted or hydroxy
substituted C.sub.2-C.sub.22 alkyl
[0193] R.sub.2 and R.sub.3 independently of each other, denote H or
linear or branched, unsubstituted or substituted C.sub.1-C.sub.12
alkyl;
[0194] (b) at least one alkanolamine of general formula (II)
##STR00014##
wherein [0195] AO is, identical or different, selected from the
group consisting of CH.sub.2--CH.sub.2--O,
CH(CH.sub.3)--CH.sub.2--O, CH.sub.2--CH(CH.sub.3)--O,
CH(C.sub.2H.sub.5)--CH--O, C(CH.sub.3).sub.2--CH.sub.2--O,
CHC(CH.sub.3).sub.2--O and CH.sub.2--CH(C.sub.2H.sub.5)--O, [0196]
m is 1, 2, 3, 4, 5, 6 or 7, and [0197] x, y independently of one
another are 0 or 1; and
[0198] (c) at least one non-ionic surfactant selected from the
group consisting of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated
oil and alkoxylated alkylamine;
[0199] to obtain a mixture of the sand and the polyurethane
binder.
[0200] Water
[0201] In a preferred embodiment, the composition that is used
according to the present invention does not contain water. In
another preferred embodiment, water is added to the composition.
The amount of water, if added to the composition, is in the range
of 0.1 wt. % to 12.0 wt. %, based on the total weight of the
composition. The disintegration of the foundry mold takes a longer
time, in the range of 100 minutes to 180 minutes when the
composition comprises water, compared to the composition without
water.
[0202] Additives
[0203] The foundry mold may further comprise at least one additive.
Additives are the materials generally added to the sand and binder
mixture to develop some special property in the sand.
[0204] Some commonly used additives for enhancing the properties of
molding and core sands are coal dust, corn flour, dextrin, sea
coal, pitch, wood flour, silica flour.
[0205] Coal Dust
[0206] Coal dust is added mainly for producing a reducing
atmosphere during casting process. This reducing atmosphere results
in any oxygen in the poles becoming chemically bound so that it
cannot oxidize the metal. It is usually added in the molding sands
for making molds for production of grey iron and malleable cast
iron castings.
[0207] Corn Flour
[0208] Corn flour belongs to the starch family of carbohydrates and
is used to increase the collapsibility of the molding and core
sand. It is completely volatilized by heat in the sand mould,
thereby leaving space between the sand grains. This allows free
movement of sand grains, which finally gives rise to mould wall
movement and decreases the mold expansion and hence defects in
castings. Corn sand if added to molding sand and core sand improves
significantly strength of the mold and core.
[0209] Dextrin
[0210] Dextrin also belongs to starch family of carbohydrates that
behaves also in a manner similar to that of the corn flour. Dextrin
increases dry strength of the molds.
[0211] Sea Coal
[0212] Sea coal is the fine powdered bituminous coal which
positions its place among the pores of the silica sand grains in
molding sand and core sand. When heated, sea coal changes to coke
which fills the pores and is unaffected by water. Because to this,
the sand grains become restricted and cannot move into a dense
packing pattern. Thus, sea coal reduces the mould wall movement and
the permeability in mold and core sand and hence makes the mold and
core surface clean and smooth.
[0213] Pitch
[0214] Pitch is distilled form of soft coal. It can be added from
0.02% to 2% in mold and core sand. Pitch enhances hot strengths,
surface finish on mold surfaces and behaves exactly in a manner
similar to that of sea coal.
[0215] Wood Flour
[0216] Wood flour is a fibrous material mixed with a granular
material like sand. Wood flour is relatively long thin fibers
prevent the sand grains from making contact with one another. wood
flour can be added in between 0.05% to 2% in mold and core sand.
Wood flour volatilizes when heated, thus allowing the sand grains
room to expand. Wood flour will increase mould wall movement and
decrease expansion defects. Wood flour also increases
collapsibility of both mold and core.
[0217] Pulverized Silica or Silica Flour
[0218] Silica flour is called as pulverized silica. Pulverized
silica can be easily added up to 3% which increases the hot
strength and finish on the surfaces of the molds and cores. It also
reduces metal penetration in the walls of the molds and cores.
[0219] In another aspect, the presently claimed invention is
directed to a composition comprising
[0220] (a) 2-hydroxypropanamide; and
[0221] (b) monoethanolamine.
[0222] In another embodiment, the presently claimed invention is
directed to a composition comprising
[0223] (a) 2-hydroxypropanamide;
[0224] (b) monoethanolamine; and
[0225] (c) at least one non-ionic surfactant;
[0226] In another embodiment, the presently claimed invention is
directed to a composition comprising
[0227] (a) 2-hydroxypropanamide;
[0228] (b) monoethanolamine; and
[0229] (c) at least one non-ionic surfactant selected from the
group consisting of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated
oil and alkoxylated alkylamine.
[0230] In yet another aspect, the presently claimed invention is
directed to the use of the composition comprising
[0231] (a) 2-hydroxypropanamide; and
[0232] (b) monoethanolamine
[0233] for disintegrating the foundry mold.
[0234] In another embodiment, the presently claimed invention is
directed to the use of the composition comprising
[0235] (a) 2-hydroxypropanamide;
[0236] (b) monoethanolamine; and
[0237] (c) at least one non-ionic surfactant;
[0238] for disintegrating the foundry mold.
[0239] In another embodiment, the presently claimed invention is
directed to the use of the composition comprising
[0240] (a) 2-hydroxypropanamide;
[0241] (b) monoethanolamine; and
[0242] (c) at least one non-ionic surfactant selected from the
group consisting of poly(C.sub.2-C.sub.4)alkylene [0243] glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic [0244] acid ester,
alkoxylated oil and alkoxylated alkylamine;
[0245] for disintegrating the foundry mold.
[0246] In yet another aspect, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0247] (i) contacting the foundry mold with a composition
comprising [0248] (a) 2-hydroxypropanamide; and [0249] (b)
monoethanolamine;
[0250] to obtain a mixture of the sand and the polyurethane
binder.
[0251] In an embodiment, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0252] (i) contacting the foundry mold with a composition
comprising [0253] (a) 2-hydroxypropanamide; [0254] (b)
monoethanolamine; and [0255] (c) at least one non-ionic
surfactant;
[0256] to obtain a mixture of the sand and the polyurethane
binder.
[0257] In another embodiment, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0258] (i) contacting the foundry mold with a composition
comprising [0259] (a) 2-hydroxypropanamide; [0260] (b)
monoethanolamine; and [0261] (c) at least one non-ionic surfactant
selected from the group consisting of poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-alkyl ether,
poly(C.sub.2-C.sub.4)alkylene glycol
mono(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated oil and
alkoxylated alkylamine;
[0262] to obtain a mixture of the sand and the polyurethane
binder.
[0263] In another aspect, the presently claimed invention is
directed to a composition comprising
[0264] (a) at least one carboxylic acid amide of general formula
(I)
##STR00015##
[0265] wherein
[0266] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl;
[0267] R.sub.2 and R.sub.3 denote methyl; and
[0268] (b) monoethanolamine.
[0269] In another embodiment, the presently claimed invention is
directed to a composition comprising
[0270] (a) at least one carboxylic acid amide of general formula
(I)
##STR00016##
[0271] wherein
[0272] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl;
[0273] R.sub.2 and R.sub.3 denote methyl;
[0274] (b) monoethanolamine; and
[0275] (c) at least one non-ionic surfactant.
[0276] In another embodiment, the presently claimed invention is
directed to a composition comprising
[0277] (a) at least one carboxylic acid amide of general formula
(I)
##STR00017##
[0278] wherein
[0279] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl;
[0280] R.sub.2 and R.sub.3 denote methyl;
[0281] (b) monoethanolamine; and
[0282] (c) at least one non-ionic surfactant selected from the
group consisting of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated
oil and alkoxylated alkylamine.
[0283] In yet another aspect, the presently claimed invention is
directed to the use of the composition comprising
[0284] (a) at least one carboxylic acid amide of general formula
(I)
##STR00018##
[0285] wherein
[0286] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl;
[0287] R.sub.2 and R.sub.3 denote methyl; and
[0288] (b) monoethanolamine,
[0289] for disintegrating the foundry mold.
[0290] In another embodiment, the presently claimed invention is
directed to the use of the composition comprising
[0291] (a) at least one carboxylic acid amide of general formula
(I)
##STR00019##
[0292] wherein
[0293] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl;
[0294] R.sub.2 and R.sub.3 denote methyl;
[0295] (b) monoethanolamine; and
[0296] (c) at least one non-ionic surfactant;
[0297] for disintegrating the foundry mold.
[0298] In another embodiment, the presently claimed invention is
directed to the use of the composition comprising
[0299] (a) at least one carboxylic acid amide of general formula
(I)
##STR00020##
[0300] wherein
[0301] R.sub.1 denotes linear or branched, unsubstituted
C.sub.2-C.sub.12 alkyl;
[0302] R.sub.2 and R.sub.3 denote methyl;
[0303] (b) monoethanolamine; and
[0304] (c) at least one non-ionic surfactant selected from the
group consisting of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated
oil and alkoxylated alkylamine;
[0305] for disintegrating the foundry mold.
[0306] In yet another aspect, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0307] (i) contacting the foundry mold with a composition
comprising [0308] (a) at least one carboxylic acid amide of general
formula (I)
[0308] ##STR00021## [0309] wherein [0310] R.sub.1 denotes linear or
branched, unsubstituted C.sub.2-C.sub.12 alkyl; [0311] R.sub.2 and
R.sub.3 denote methyl; and [0312] (b) monoethanolamine;
[0313] to obtain a mixture of the sand and the polyurethane
binder.
[0314] In an embodiment, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0315] (i) contacting the foundry mold with a composition
comprising [0316] (a) at least one carboxylic acid amide of general
formula (I)
[0316] ##STR00022## [0317] wherein [0318] R.sub.1 denotes linear or
branched, unsubstituted C.sub.2-C.sub.12 alkyl; [0319] R.sub.2 and
R.sub.3 denote methyl; [0320] (b) monoethanolamine; and [0321] (c)
at least one non-ionic surfactant;
[0322] to obtain a mixture of the sand and the polyurethane
binder.
[0323] In another embodiment, the presently claimed invention is
directed to a method for disintegrating the foundry mold comprising
sand and a polyurethane binder comprising the step of
[0324] (i) contacting the foundry mold with a composition
comprising [0325] (a) at least one carboxylic acid amide of general
formula (I)
[0325] ##STR00023## [0326] wherein [0327] R.sub.1 denotes linear or
branched, unsubstituted C.sub.2-C.sub.12 alkyl; [0328] R.sub.2 and
R.sub.3 denote methyl; [0329] (b) monoethanolamine; and [0330] (c)
at least one non-ionic surfactant selected from the group
consisting of poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-alkyl ether, poly(C.sub.2-C.sub.4)alkylene
glycol mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated
oil and alkoxylated alkylamine;
[0331] to obtain a mixture of the sand and the polyurethane
binder.
[0332] In another preferred embodiment, the presently claimed
invention relates to a method for disintegrating the foundry mold
comprising sand and a polyurethane binder comprising the steps
of
[0333] (i) contacting the foundry mold with a composition
comprising
[0334] (a) at least one carboxylic acid amide of general formula
(I)
##STR00024##
[0335] wherein
[0336] R.sub.1 denotes linear or branched, unsubstituted or hydroxy
substituted C.sub.2-C.sub.22 alkyl
[0337] R.sub.2 and R.sub.3 independently of each other, denote H or
linear or branched, unsubstituted or substituted C.sub.1-C.sub.12
alkyl; and
[0338] (b) at least one alkanolamine of general formula (II)
##STR00025##
wherein
[0339] AO is, identical or different, selected from the group
consisting of CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O,
[0340] is 1, 2, 3, 4, 5, 6 or 7, and
[0341] x, y independently of one another are 0 or 1,
[0342] to obtain a mixture of the sand and the polyurethane
binder;
[0343] (ii) separating the sand from the mixture obtained in step
(i); and
[0344] (iii) drying the sand obtained in step (ii).
[0345] The sand is separated from the mixture of sand and
polyurethane binder by one or more methods known in the art, namely
reconditioning, thermal methods, dry methods etc. Reconditioning
merely contemplates that the used sand is passed over magnetic
pulleys, through lump breakers and screens, and then aerated to
remove fines. Thermal methods of treatment, include a roasting
furnace, a fluid bed furnace and a rotary kiln. The thermal calcine
system subjects the sand to temperatures in the range of
1200.degree.-1500.degree. in the presence of excess oxygen, thereby
removing carbonaceous additives. Dry method includes mechanical
methods which comprise impacting sand grains to fracture the
"shells" of old bonds from individual grains. There are several
modes that would fall under the category of being dry, including
(a) centrifuging sand against an enclosure; (b) a pneumatically
shooting sand against a target, or additionally causing two
separate streams of sand to intersect for scrubbing; and (c)
mulling at low kinetic energy levels to squeeze the sand grains
under pressure of a wheel.
[0346] The sand is dried by processes known to a person skilled in
the art. The sand is passed through a fluid bed furnace. Hot sand
is then passed through a cooling drum where the sand is
subsequently cleaned and cooled to room temperature by means of
cooling air. The sand obtained after drying is routinely screened
and returned to the system for reuse. The sand can be recycled and
reused in the foundry for making foundry molds for a number of
cycles.
[0347] However, as the sand is repeatedly used, the particles
eventually become too fine for the molding process; and, hence can
also be put to other application, if this sand cannot be used for
moulding, such as: [0348] 1. Asphalt Concrete: Substitution of up
to 15% spent sand for conventional asphalt concrete fine aggregate.
[0349] 2. Compost Additive: Bulking agent for composted yard waste,
to produce topsoil or topsoil additive. [0350] 3. Concrete:
Substitution for regular sand in structural grade concrete, at low
percentages. [0351] 4. Bricks and Pavers: Encapsulation in a
proprietary, high pressure, pozzolanic process that can encapsulate
and chemically bind various waste materials in C-grade fly ash (a
fine particulate ash produced by coal-burning electrical power
plants). The ambient-temperature process results in bricks that are
cost effective and can be shaped to meet end-user requirements
[0352] The present invention offers one or more of following
advantages: [0353] 1. The method of the present invention can be
used for a variety of foundry molds with varied sand and binder
composition. [0354] 2. Small amount of the composition is effective
in disintegrating the foundry mold.
[0355] In the following, specific embodiments of the present
invention are described:
[0356] 1. A method for disintegrating the foundry mold comprising
sand and a polyurethane based binder comprising at least the step
of [0357] (i) contacting the foundry mold with a composition
comprising [0358] (a) at least one carboxylic acid amide of general
formula (I)
[0358] ##STR00026## wherein R.sub.1 denotes linear or branched,
unsubstituted or hydroxy substituted C.sub.2-C.sub.22 alkyl R.sub.2
and R.sub.3 independently of each other, denote H or linear or
branched, unsubstituted or substituted C.sub.1-C.sub.12 alkyl;
and
[0359] (b) at least one alkanolamine of general formula (II)
##STR00027##
wherein
[0360] AO is, identical or different, selected from the group
consisting of CH.sub.2--CH.sub.2--O, CH(CH.sub.3)--CH.sub.2--O,
CH.sub.2--CH(CH.sub.3)--O, CH(C.sub.2H.sub.5)--CH--O,
C(CH.sub.3).sub.2--CH.sub.2--O, CHC(CH.sub.3).sub.2--O and
CH.sub.2--CH(C.sub.2H.sub.5)--O,
[0361] m is 1, 2, 3, 4, 5, 6 or 7, and
[0362] x, y independently of one another are 0 or 1;
[0363] to obtain a mixture of the sand and the polyurethane
binder.
[0364] 2. The method according to embodiment 1, wherein the sand is
selected from the group consisting of natural silica sand, clay,
green sand, quartz sand, chromite sand, olivine sand, special sands
and zirconium sand.
[0365] 3. The method according to embodiment 1, wherein the
polyurethane based binder comprises polyurethane, water glass and
at least one resin that is different from polyurethane.
[0366] 4. The method according to embodiment 1, wherein R.sub.1 is
selected from the group consisting of ethyl, n-propyl, n-butyl,
n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl,
n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl,
n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, n-heneicosyl,
n-docosyl, isopropyl, isobutyl, isopentyl, isohexyl, isoheptyl,
isooctyl, isononyl, isodecyl, isoundecyl, isododecyl, isotridecyl,
isotetradecyl, isopentadecyl, isohexadecyl, isoheptadecyl,
isooctadecyl, isononadecyl, isoeicosyl, isoheneicosyl, isodocosyl,
t-butyl, 1-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl,
1-hydroxybutyl, 2-hydroxybutyl, 2-hydroxybutyl, 1-hydroxypentyl,
2-hydroxypentyl, 3-hydroxypentyl, 4-hydroxypentyl, 1-hydroxyhexyl,
2-hydroxyhexyl, 3-hydroxyhexyl, 4-hydroxyhexyl and
5-hydroxyhexyl.
[0367] 5. The method according to embodiment 1, wherein R.sub.1 is
selected from the group comprising of ethyl, n-propyl, n-butyl,
n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, isooctyl,
isopropyl, isobutyl, isopentyl, isohexyl, isoheptyl, isononyl,
isodecyl, 1-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl,
1-hydroxybutyl, 2-hydroxybutyl, 1-hydroxypentyl, 2-hydroxypentyl,
3-hydroxypentyl, 4-hydroxypentyl, 1-hydroxyhexyl, 2-hydroxyhexyl,
3-hydroxyhexyl, 4-hydroxyhexyl and 5-hydroxyhexyl.
[0368] 6. The method according to embodiment 1, wherein R.sub.2 and
R.sub.3 independently of each other, are selected from the group
consisting of H, methyl, ethyl, n-propyl, n-butyl, n-pentyl,
n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl,
isopropyl, isobutyl, isopentyl, isohexyl, isoheptyl, isooctyl,
isononyl, isodecyl, isoundecyl, isododecyl and t-butyl.
[0369] 7. The method according to one or more of embodiment 1 to 6,
wherein R.sub.2 and R.sub.3 independently of each other, are
selected from the group consisting of H, methyl, ethyl, n-propyl,
n-butyl, isopropyl, isobutyl and t-butyl.
[0370] 8. The method according to one or more of embodiments 1 to
7, wherein R.sub.2 and R.sub.3 are methyl.
[0371] 9. The method according to embodiment 1, wherein m is 1, 2
or 3.
[0372] 10. The method according to embodiment 1, wherein x and y
are 0.
[0373] 11. The method according to one or more of embodiment 1 to
10, wherein the at least one carboxylic acid amide of general
formula (I) and the at least one alkanolamine of general formula
(II) are present in a molar ratio of 5:1 to 1:5.
[0374] 12. The method according to embodiment 1, wherein contacting
in step (i) is achieved by immersing the foundry mold at a
temperature in the range of 10 to 200.degree. C.
[0375] 13. The method according to embodiment 1, wherein the step
(i) is carried out for a time period of .gtoreq.10 min. to
.ltoreq.60 min.
[0376] 14. The method according to one or more of embodiments 1 to
13, further comprising the step of [0377] (ii) separating the sand
from the mixture obtained in step (i).
[0378] 15. The method according to one or more of embodiments 1 to
14, further comprising the step of [0379] (iii) drying the sand
obtained in step (ii).
[0380] 16. The method according to embodiment 1, wherein the
composition comprises at least one surfactant.
[0381] 17. The method according to embodiment 16, wherein the at
least one surfactant is a non-ionic surfactant.
[0382] 18. The method according to embodiment 17, wherein the
non-ionic surfactant is selected from the group consisting of
poly(C.sub.2-C.sub.4)alkylene glycol mono-(C.sub.8-C.sub.22)-alkyl
ether, poly(C.sub.2-C.sub.4)alkylene glycol
mono-(C.sub.8-C.sub.22)-carboxylic acid ester, alkoxylated oil and
alkoxylated alkylamine.
[0383] 19. The method according to embodiments 17 or 18, wherein
the non-ionic surfactant is selected from alkyl polyethylene glycol
ether, ethoxylated castor oil and oleyl amine ethoxylate.
[0384] 20. The method according to one or more of embodiments 1 to
19, wherein the composition comprises water.
[0385] 21. A composition comprising [0386] (a)
2-hydroxypropanamide; and [0387] (b) monoethanolamine.
[0388] 22. Use of the composition according to embodiment 21 for
disintegrating foundry mold.
[0389] 23. A method for disintegrating the foundry mold comprising
sand and binder comprising the step of [0390] (i) contacting the
foundry mold with the composition according to embodiment 21;
[0391] to obtain a mixture of the sand and the binder.
EXAMPLES
[0392] Compounds
[0393] Monoethanol Amine
[0394] Agnique.RTM. AMD 3L (N,N-Dimethyl lactamide)
[0395] Lutensol.RTM. FA12 (Oleylamine ethoxylate)
[0396] Lutensol.RTM. XL60 (C.sub.10-Guerbet alcohol
ethoxylates)
[0397] Emulan.RTM. EL (Castor oil ethoxylate)
[0398] Agnique.RTM. AMD 10 (C.sub.10 fatty acid
N,N-Dimethylamide)
[0399] Agnique.RTM. AMD 810 (C.sub.8/C.sub.10 fatty acid
N,N-Dimethylamide) are available from BASF SE, Ludwigshafen,
Germany.
[0400] Foundry mold sample of size 9 cm.times.2.2 cm.times.2.2 cm,
made of PU-sand composite was pre-pared according to state of the
art.
[0401] General Procedure
[0402] The foundry mold sample was immersed (one-third) in the
composition as disclosed in Examples 1 to 6, at room temperature.
The time of collapse of the sample was determined. The time of
collapse is the time taken for the disintegration of the foundry
mold sample completely resulting into the mixture of sand and
binder.
TABLE-US-00001 Amount of carboxylic Amount Amount acid of of Time
of Carboxylic amide alkanolamine surfactant collapse Example acid
amide (wt. %) Alkanolamine (wt. %) Surfactant (wt. %) (minutes) 1
Agnique .RTM. 75 monoethanol 25 none -- 60 AMD 3L amine 2 Agnique
.RTM. 25 monoethanol 25 Lutensol .RTM. 50 60 AMD 3L amine XL60 3
Agnique .RTM. 50 monoethanol 25 Lutensol .RTM. 25 60 AMD 3L amine
FA12 4 Agnique .RTM. 50 monoethanol 25 Emulan .RTM. 25 60 AMD 3L
amine EL 5 Agnique .RTM. 25 monoethanol 25 Lutensol .RTM. 50 35 AMD
10 amine XL60 6 Agnique .RTM. 25 monoethanol 25 Lutensol .RTM. 50
45 AMD 810 amine XL60
* * * * *