SYSTEME DE NETTOYAGE UTILISANT UN SOLVANT DE NETTOYAGE ORGANIQUE ET UN SOLVANT LIQUIDE SOUS PRESSION

CLEANING SYSTEM UTILIZING AN ORGANIC CLEANING SOLVENT AND A PRESSURIZED FLUID SOLVENT

Abrégé français

L'invention concerne un système de nettoyage utilisant un solvant de nettoyage organique et un solvant liquide sous pression. Ledit système ne présente aucun cycle de séchage à air chaud par évaporation classique. Il utilise en revanche la solubilité du solvant organique dans un solvant liquide sous pression ainsi que les propriétés physiques du solvant liquide sous pression. Après un cycle de nettoyage au solvant organique, on extrait à grande vitesse le solvant des textiles dans un tambour tournant comme on en extrait les solvants classiques dans des séchoirs de nettoyage à air chaud par évaporation classiques. Au lieu d'exécuter un cycle de séchage classique, on trempe ensuite les textiles extraits dans un solvant liquide sous pression afin d'en extraire le solvant organique résiduel, puisque le solvant organique est soluble dans le solvant liquide sous pression. Une fois les textiles trempés dans le solvant liquide sous pression, celui-ci est pompé à partir du tambour. Enfin, le tambour est mis en dépression à la pression atmosphérique afin que le solvant liquide sous pression résiduel puisse s'évaporer, rendant des textiles propres exempts de solvant. De préférence, le solvant organique est l'éther n-butyl de dipropylène glycol, l'éther n-butyl tripropylène glycol ou l'éther de tripropylène glycol de méthyle, un mélange de ceux-ci, ou un solvant semblable, le solvant liquide sous pression étant de préférence du dioxyde de carbone densifié.

Abrégé anglais

A cleaning system that utilizes an organic cleaning solvent and pressurized
fluid solvent is disclosed. The system
has no conventional evaporative hot air drying cycle. Instead, the system
utilizes the solubility of the organic solvent in pressurized
fluid solvent as well as the physical properties of pressurized fluid solvent.
After an organic solvent cleaning cycle, the solvent is
extracted from the textiles at high speed in a rotating drum in the same way
conventional solvents are extracted from textiles in
conventional evaporative hot air dry cleaning machines. Instead of proceeding
to a conventional drying cycle, the extracted textiles
are then immersed in pressurized fluid solvent to extract the residual organic
solvent from the textiles. This is possible because the
organic solvent is soluble in pressurized fluid solvent. After the textiles
are immersed in pressurized fluid solvent, pressurized fluid
solvent is pumped from the drum. Finally, the drum is de-pressurized to
atmospheric pressure to evaporate any remaining pressurized
fluid solvent, yielding clean, solvent free textiles. The organic solvent is
preferably dipropylene glycol n-butyl ether, tripropylene
glycol n-butyl ether or tripropylene glycol methyl ether, a mixture thereof,
or a similar solvent and the pressurized fluid solvent is
preferably densified carbon dioxide.

Revendications

CLAIMS
1. A process for cleaning a substrate selected from the group consisting of a
textile,
a flexible structure, a precision structure, a delicate structure, and a
porous structure, comprising:
cleaning the substrate by removing substantially all of a contaminant with at
least one
organic solvent in absence of liquid carbon dioxide, the organic solvent
comprising less than
50% by weight water; and
removing the organic solvent from the substrates using at least one
pressurized fluid
solvent;
wherein the organic solvent is of the structural formula:
<IMG>
wherein x, y, and z each is zero or one;
at least one of x, y, and z is one;
R' is C j H2j+1 wherein j is an integer between one and (13-3(x+y+z)),
inclusive; and
R1-3 are independently H or CH3;
wherein when the pressurized fluid solvent is liquid carbon dioxide, the
liquid carbon
dioxide is at a subcritical condition.
2. A process for cleaning a substrate selected from the group consisting of a
textile,
a flexible structure, a precision structure, a delicate structure, and a
porous structure, comprising:

cleaning the substrate by removing substantially all of a contaminant with at
least one
organic solvent in absence of liquid carbon dioxide, the organic solvent
comprising less than
50% by weight water; and
removing the organic solvent from the substrates using at least one
pressurized fluid
solvent;
wherein the organic solvent is of the structural formula:
<IMG>
wherein x, y, and z each is zero or one;
at least one of x, y, and z is one;
R" is benzyl, phenyl, partially or fully fluorinated benzyl or phenyl, C j
H2j+1, or C j H a F b
wherein j is an integer between one and (13-3(x+y+z)), inclusive, a and b each
is independently
an integer between zero and 2j+1, inclusive, and a+b=2j+1;
R1-12 are independently C m H n F p or C d H e F g where m is an integer
between zero and two,
inclusive, n and p are integers between zero and five, inclusive and n+p=2m+1,
d is an integer
between zero and two, inclusive, e and g are integers between zero and five,
inclusive, and e+g
=2d+1; and
R' is O, S, carbonyl or ester;
wherein when the pressurized fluid solvent is liquid carbon dioxide, the
liquid carbon
dioxide is at a subcritical condition.

3. The process of claim 2 wherein:
R' is O;
R" is C j H2j+1;
R1-3 are independently H or CH3; and
R4-12 each is H.
4. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is C j H2j+1;
R1-3 are independently H or CH3; and
R4-12 each is H.
5. The process of claim 2 wherein:
R' is O;
R" is C j H2j+1;
R1-3 are independently H, CH3, or C2H5; and
at least one of R1-3 is CH2CH3; and
R4-12 are each H.
6. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is C j H2j+1;
R1-3 are independently H, CH3, or C2H5; and
at least one of R1-3 is CH2CH3; and
R4-12 are each H.
7. The process of claim 2 wherein:
R' is O;
R" is C j H2j+1;
R1-9 are each H;
R10-12 are independently H or CH3; and
at least one of R10-12 is CH3.

8. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is C j H2j+1;
R1-9 are each H;
R10-12 are independently H or CH3; and
at least one of R10-12 is CH3.
9. The process of claim 2 wherein:
R' is O;
R" is C j H2j+1;
R1-9 are each H;
R10-12 are independently H, CH3, or C2H5; and
at least one of R10-12 is CH2CH3.
10. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is C j H2j+1;
R1-9 are each H;
R10-12 are independently H, CH3, or C2H5; and
at least one of R10-12 is CH2CH3.
11. The process of claim 2 wherein:
R' is O;
R" is C j H a F b;
R1-3 are independently H, F, CH3, CH2F, CHF2, or CF3;
And at least one is CH3, CH2F, CHF2, or CF3; and
R4-12 are independently H or F.
12. The process of claim 2 wherein:
R' is S, carbonyl, or ester;
R" is C j H a F b;
R1-3 are independently H, F, CH3, CH2F, CHF2, or CF3;
And at least one is CH3, CH2F, CHF2, or CF3; and
R4-12 are independently H or F.

13. The process of claim 2 wherein:
R1-3 are independently C m H n F p;
at least one of R1-3 is C2H n F p;
R4-12 are independently H or F;
R' is O; and
R" is C j H a F b.
14. The process of claim 2 wherein:
R1-3 are independently C m H n F p;
at least one of R1-3 is C2H n F p;
R4-12 are independently H or F;
R' is S, carbonyl or ester; and
R" is C j H a F b.
15. The process of claim 2 wherein:
R1-9 are independently H or F;
R10-12 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is CH3, CH2F, CHF2 or CF3;
R' is O; and
R" is C j H a F b.
16. The process of claim 2 wherein:
R1-9 are independently H or F;
R10-12 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is CH3, CH2F, CHF2 or CF3;
R' is S, carbonyl or ester; and
R" is C j H a F b.
17. The process of claim 2 wherein:
R' is O;
R" is C j H a F b;
R1-3 are independently C m H n F p;
R4-9 are independently H or F; and
R10-12 are independently C d H e F g.

18. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is C j H a F b;
R1-3 are independently C m H n F p;
R4-9 are independently H or F; and
R10-12 are independently C d H e F g.
19. The process of claim 2 wherein:
R' is O;
R" is benzyl or phenyl;
R1-3 are independently H, CH3, or C2H5;
at least one of R1-3 is CH2CH3; and
R4-12 are each H.
20. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is benzyl or phenyl;
R1-3 are independently H, CH3, or C2H5;
at least one of R1-3 is CH2CH3; and
R4-12 are each H.
21. The process of claim 2 wherein:
R' is O;
R" is benzyl or phenyl;
R1-9 are each H;
R10-12 are independently H or CH3; and
at least one of R10-12 is CH3.
22. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is benzyl or phenyl;
R1-9 are each H;
R10-12 are independently H or CH3; and
at least one of R10-12 is CH3.

23. The process of claim 2 wherein:
R' is O;
R" is benzyl or phenyl;
R1-9 are each H;
R10-12 are independently H, CH3, or C2H5; and
at least one of R10-12 is CH2CH3.
24. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is benzyl or phenyl;
R1-9 are each H;
R10-12 are independently H, CH3, or C2H5; and
at least one of R10-12 is CH2CH3.
25. The process of claim 2 wherein:
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-3 are independently C m H n F p;
at least one of R1-3 is C2H n F p;
R4-12 are independently H or F; and
R'is O.
26. The process of claim 2 wherein:
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-3 are independently C m H n F p;
at least one of R1-3 is C2H n F p;
R4-12 are independently H or F; and
R' is S, carbonyl or ester.
27. The process of claim 2 wherein:
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-9 are independently H or F;
R10-12 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is CH3, CH2F, CHF2 or CF3; and
R'is O.

28. The process of claim 2 wherein:
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-9 are independently H or F;
R10-12 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is CH3, CH2F, CHF2 or CF3; and
R' is S, carbonyl or ester.
29. The process of claim 2 wherein:
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-9 are independently H or F;
R10-12 are independently C m H n F p;
at least one of R10-12 is C2H n F p; and
R'is O.
30. The process of claim 2 wherein:
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-9 are independently H or F;
R10-12 are independently C m H n F p;
at least one of R10-12 is C2H n F p; and
R' is S, carbonyl or ester.
31. The process of claim 2 wherein:
R' is O;
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-3 are independently C m H n F p;
R4-9 are independently H or F; and
R10-12 are independently C d H e F g.
32. The process of claim 2 wherein:
R' is S, carbonyl or ester;
R" is benzyl, phenyl, or partially or fully fluorinated benzyl or phenyl;
R1-3 are independently C m H n F p;
R4-9 are independently H or F; and
R10-12 are independently C d H e F g.
33. A process for cleaning a substrate selected from the group consisting of a
textile,
a flexible structure, a precision structure, a delicate structure, and a
porous structure, comprising:

cleaning the substrate by removing substantially all of a contaminant with at
least one
organic solvent in absence of liquid carbon dioxide, the organic solvent
comprising less than
50% by weight water; and
removing the organic solvent from the substrates using at least one
pressurized fluid
solvent;
wherein the organic solvent is of the structural formula:
<IMG>
wherein x, y, and z each is zero or one;
at least one of x, y, and z is one;
R" is C j H2j+1 or C j H u F v and R IV is C k H2k+1 or C k H r F s wherein j
and k are each an
integer between one and (13-3(x+y+z)), inclusive, and j+k is an integer
between two and (13-
3(x+y+z)), inclusive, u and v are each an integer between zero and 2j+1,
inclusive, and
u+v=2j+1, and r and s are each an integer between zero and 2k+1, inclusive,
and r+s=2k+1, and
if k equals zero, then s equals zero;
R1-3 and R10-12 are independently C m H n F p, where m is an integer between
zero and two,
inclusive, n and p are integers between zero and five, inclusive and n+p=2m+1;
R4-9 are independently H, F, CH3, CH2F, CHF2, or CF3; and
R' is O, S, carbonyl or ester, and if R' is O or S and j equals zero then v
equals zero;
wherein when the pressurized fluid solvent is liquid carbon dioxide, the
liquid carbon
dioxide is at a subcritical condition.

34. The process of claim 33 wherein:
R' is O;
R" is C j H2j+i;
R IV is C k H2k+1;
R1-3 are independently H or CH3; and
R4-12 are each H.
35. The process of claim 33 wherein:
R' is S, carbonyl or ester;
R" is C j H2k+1;
R IV is C k H2k+1;
R1-3 are independently H or CH3; and
R4-12 are each H.
36. The process of claim 33 wherein:
R' is O;
R" is C j H2k+1;
R IV is C k H2k+1;
R1-3 are independently H, CH3, or C2H5;
at least one of R1-3 is CH2CH3; and
R4-12 are each H.
37. The process of claim 33 wherein:
R' is S, carbonyl or ester;
R" is C j H1j+1;
R IV is C k H2k+1;
R1-3 are independently H, CH3, or C2H5;
at least one of R1-3 is CH2CH3; and
R4-12 are each H.
38. The process of claim 33 wherein:
R' is O;
R" is C j H2j+1;
R IV is C k H2k+1;
R1-9 are each H;
R10-12 are independently H or CH3; and
at least one of R10-12 is CH3.

39. The process of claim 33 wherein:
R' is S, carbonyl or ester;
R" is C j H2j+1;
R IV is C k H2k+1;
R1-9 are each H;
R10-12 are independently H or CH3; and
at least one of R10-12 is CH3.
40. The process of claim 33 wherein:
R' is O;
R" is C j H2k+n;
R IV is C k H2k+1;
R1-9 are each H;
R10-12 are independently H, CH3, or C2H5; and
at least one of R10-12 is CH2CH3.
41. The process of claim 33 wherein:
R' is S, carbonyl or ester;
R" is C j H2j+1;
R IV is C k H2k+1;
R1-9 are each H;
R10-12 are independently H, CH3, or C2H5; and
at least one of R10-12 is CH2CH3.
42. The process of claim 33 wherein:
R1-3 are independently H, F, CH3, CH2F, CHF2, or CF3;
R4-12 are independently H or F;
R' is O;
R" is C j H u F v; and
R IV is C k H r F s.

43. The process of claim 33 wherein:
R1-3 are independently H, F, CH3, CH2F, CHF2, or CF3;
R4-12 are independently H or F;
R' is S, carbonyl or ester;
R" is C j H u F v; and
R IV is C k H r F s.
44. The process of claim 33 wherein:
at least one of R1-3 is C2H n F p;
R4-12 are each independently H or F;
R' is O;
R" is C j H u F v; and
R IV is C k H r F s.
45. The process of claim 33 wherein:
at least one of R1-3 is C2H n F p;
R4-21 are each independently H or F;
R' is S, carbonyl or ester;
R" is C j H u F v; and
R IV is C k H r F s.
46. The process of claim 33 wherein:
R1-9 are independently H or F;
R10-12 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is CH3, CH2F, CHF2 or CF3;
R' is O;
R" is C j H u F v; and
R IV is C k H r F s.

47. The process of claim 33 wherein:
R1-9 are independently H or F;
R10-12 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is CH3, CH2F, CHF2 or CF3;
R' is S, carbonyl or ester;
R" is C j H u F v; and
R IV is C k H r F s.
48. The process of claim 33 wherein:
R1-9 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is C2H n F p;
R' is O;
R" is C j H u F v; and
R IV is C k H r F s.
49. The process of claim 33 wherein:
R1-9 are independently H, F, CH3, CH2F, CHF2 or CF3;
at least one of R10-12 is C2H n F p;
R' is S, carbonyl or ester;
R" is C j H u F v; and
R IV is C k H r F s.
50. A process for cleaning a substrate selected from the group consisting of a
textile,
a flexible structure, a precision structure, a delicate structure, and a
porous structure, comprising:
cleaning the substrate by removing substantially all of a contaminant with at
least one
organic solvent in absence of liquid carbon dioxide, the organic solvent
comprising less than
50% by weight water; and
removing the organic solvent from the substrates using at least one
pressurized fluid
solvent;
wherein the organic solvent is of the structural formula:

<IMG>
wherein x, y, and z are each zero or one;
at least one of x, y, and z is one;
R" is selected from the group consisting of:
H;
<IMGS>
wherein R"' is H, F or combinations of H and F;
R IV is selected from the group consisting of:
H;
<IMGS> ; and

wherein R v is H, F or combinations of H and F; and
when R" is H or F, R IV is not H or F;
R1-3 are independently H, F, CH3, CH2F, CHF2 or CF3; and
R4-12 are independently H or F;
wherein when the pressurized fluid solvent is liquid carbon dioxide, the
liquid carbon
dioxide is at a subcritical condition.
51. The process of claim 50 wherein:
R IV is:
H
or
<IMG>
wherein R v is H, F or combinations of H and F; and
R" is:
<IMG>
wherein R"' is H, F or combinations of H and F.
52. The process of claim 50 wherein:
R" is:
H
or
<IMG>

wherein R"' is H, F or combinations of H and F; and
R IV is:
<IMG>
wherein R v is H, F or combinations of H and F.
53. The process of claim 50 wherein:
R" is:
H;
F; or
<IMG>
wherein R"' is H, F or combinations of H and F; and
R IV is:
H;
<IMG>
wherein R V is H, F or combinations of H and F; and
when R" is H or F, R IV is not H or F.
54. The process of claim 50 wherein:
R1-3 are independently H or CH3;
R4-12 are each H;
R IV is:
H
or
<IMG>

and
R" is:
<IMG>
55. The process of claim 50 wherein:
R1-3 are independently H or CH3;
R4-12 are each H;
R" is:
H
or
<IMG>
and
R IV is:
<IMG>
56. The process of claim 50 wherein:
R1-3 are independently H or CH3;
R4-12 are each H;
R" is:
H;
or
<IMG>
R IV is:
H;

or
<IMG>
and when R" is H, R IV is not H.
57. A process for cleaning a substrate selected from the group consisting of a
textile,
a flexible structure, a precision structure, a delicate structure, and a
porous structure, comprising:
cleaning the substrate by removing substantially all of a contaminant with at
least one
organic solvent in absence of liquid carbon dioxide, the organic solvent
comprising less than
50% by weight water; and
removing the organic solvent from the substrates using at least one
pressurized fluid
solvent;
wherein the organic solvent is of the structural formula:
<IMG>
wherein R' is
<IMG>
R" is independently

<IMG>
wherein R''' is O and j is 1 or R''' is N and j is 2;
n is an integer between zero and two;
R IV are each independently H, CH3 or CH2CH3 and k is an integer between zero
and two
inclusive; and
wherein R is CyH2y+1 and y is an integer between one and (12-(3k+3n+x))
inclusive,
and x is an integer between one and (12-(3k+y)), inclusive;
wherein when the pressurized fluid solvent is liquid carbon dioxide, the
liquid carbon
dioxide is at a subcritical condition.
58. A process for cleaning a substrate selected from the group consisting of a
textile,
a flexible structure, a precision structure, a delicate structure, and a
porous structure, comprising:
cleaning the substrate by removing substantially all of a contaminant with at
least one
organic solvent in absence of liquid carbon dioxide, the organic solvent
comprising less than
50% by weight water; and
removing the organic solvent from the substrates using at least one
pressurized fluid
solvent;
wherein the organic solvent is of the structural formula:
<IMG>

wherein R''' is O or NH;
R IV are each independently H, CH3 or CH2CH3 and k is an integer between zero
and two
inclusive; and
wherein R is CyH2y+1 and Y is an integer between one and (12-(3k+x))
inclusive, and x
is an integer between one and (12-(3k+y)), inclusive;
wherein when the pressurized fluid solvent is liquid carbon dioxide, the
liquid carbon
dioxide is at a subcritical condition.
59. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the organic
solvent
contains 5 or more carbon atoms.
60. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the organic
solvent
has a flash point of greater than 200° F.
61. The process of claim 1, wherein the organic solvent is selected from the
group
consisting of propylene glycol t-butyl ether, dipropylene glycol methyl ether,
tripropylene glycol
methyl ether, dipropylene glycol n-butyl ether, dipropylene glycol n-propyl
ether, and
tripropylene glycol n-butyl ether.
62. The process of any of claim 1, 2, 33, 50, 57, or 58, wherein the organic
solvent
further comprises one or more co-solvents, detergents, or additives to enhance
cleaning
capability.
63. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the
pressurized fluid
solvent is between approximately 5° C to approximately 30° C.
64. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the
pressurized fluid
solvent comprises liquid carbon dioxide.

65. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the
pressurized fluid
solvent is at a pressure of between approximately 600 pounds per square inch
to approximately
1050 pounds per square inch.
66. The process of any of claims 1, 2, 33, 50, 5?, or 58, wherein the
pressurized fluid
solvent is at a pressure of between approximately 570 pounds per square inch
to approximately
830 pounds per square inch.
67. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the
pressurized fluid
solvent comprises xenon, nitrous oxide, or sulfur hexafluoride.
68. The process of claim 67, wherein the pressurized fluid solvent is
compressed to a
subcritical condition.
69. The process of claim 68, wherein the pressurized fluid solvent is a
liquid.
70. The process of claim 67, wherein the pressurized fluid solvent is
compressed to a
supercritical condition.
71. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the textile
comprises
a fabric, an article of clothing, a protective cover, a carpet, upholstery,
furniture, or a window
treatment.
72. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the
contaminant
comprises an insoluble particulate.
73. The process of any of claims 1, 2, 33, 50, 57, or 58, wherein the
contaminant
comprises an organic solvent soluble oil, or an organic solvent soluble
grease.
74. The process of claim 2, wherein:
R1-3 are independently selected from the group consisting of H, F, CH3,
CH2CH3, CH2F,
CHF2, CF3, and C m H n F p;

R4-9 are independently selected from the group consisting of H and F; and
R10-12 are independently selected from the group consisting of H, F, CH3,
CH2CH3, CH2F,
CHF2, CF3, C d H e F g, and C m H n F p.
75. The process of claim 74, wherein R1-3 are independently selected from the
group
consisting of H and CH3.
76. The process of claim 74, wherein R1-3 are independently selected from the
group
consisting of H, CH3, and CH2CH3.
77. The process of claim 74, wherein R1-3 are independently selected from the
group
consisting of H, F, CH3, CH2F, CHF2, and CF3.
78. The process of claim 74, wherein R1-3 are C m H n F p.
79. The process of claim 74, wherein R4-9 are H.
80. The process of claim 74, wherein R4-9 are F.
81. The process of claim 74, wherein R1-12 are H.
82. The process of claim 74, wherein R10-12 are independently selected from
the group
consisting of H or F.
83. The process of claim 74, wherein R10-12 are independently selected from
the group
consisting of H and CH3.
84. The process of claim 74, wherein R10-12 are independently selected from
the group
consisting of H, CH3, and CH2CH3.
85. The process of claim 74, wherein R10-12 are independently selected from
the group
consisting of H, F, CH3, CH2F, CHF2, and CF3.
86. The process of claim 74, wherein R10-12 are C d H e F g.
87. The process of claim 74, wherein R10-12 are C m H n F p.

88. The process of claim 2, wherein R' is O.
89 The process of claim 2, wherein R' is selected from the group consisting of
S,
carbonyl, and ester.
90. The process of claim 33, wherein:
R1-3 and R10-12 are independently selected from the group consisting of H, F,
CH3,
CH2CH3, CH2F, CHF2, CF3, and C m H n F p; and
R4-9 are independently selected from the group consisting of H, F, and CH3.
91. The process of claim 90, wherein R1-3 and R10-12 are H.
92. The process of claim 90, wherein R1-3 and R10-12 are independently
selected from
the group consisting of H and CH3.
93. The process of claim 90, wherein R1-3 and R10-12 are independently
selected from
the group consisting of H, CH3, and CH2CH3.
94. The process of claim 90, wherein R1-3 and R10-12 are independently
selected from
the group consisting of H, F, CH3,CH2F, CHF2, and CF3.
95. The process of claim 90, wherein R1-3 and R10-12 are C m H n F p.
96. The process of claim 90, wherein R4-9 are H.
97. The process of claim 90, wherein R4-9 are independently selected from the
group
consisting of H and F.
98. The process of claim 33, wherein R' is O.
99. The process of claim 33, wherein R" is C j H2j+1
.
100. The process of claim 33, wherein R'' is C j H u F v.
101. The process of claim 33, wherein R IV is C k H2k+1

102. The process of claim 33, wherein R IV is C k H r F s.
::ODMA\PCDOCS\CCT\426569\4

Description

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
CLEANING SYSTEM UTILIZING AN ORGANIC CLEANING
SOLVENT AND A PRESSURIZED FLUID SOLVENT
BACKGROUND
Field of the Invention
The present invention relates generally to cleaning systems, and more
specifically to substrate cleaning systems, such as textile cleaning systems,
utilizing
an organic cleaning solvent and a pressurized fluid solvent.
Related Art
A variety of methods and systems are known for cleaning substrates such as
textiles, as well as other flexible, precision, delicate, or porous structures
that are
sensitive to soluble and insoluble contaminants. These known methods and
systems
typically use water, perchloroethylene, petroleum, and other solvents that are
liquid
at or substantially near atmospheric pressure and room temperature for
cleaning the
substrate.
Such conventional methods and systems generally have been considered
satisfactory for their intended purpose. Recently, however, the desirability
of
employing these conventional methods and systems has been questioned due to
environmental, hygienic, occupational hazard, and waste disposal concerns,
among
other things. For example, perchloroethylene frequently is used as a solvent
to
clean delicate substrates, such as textiles, in a process referred to as "dry
cleaning."
Some locales require that the use and disposal of this solvent be regulated by
environmental agencies, even when only trace amounts of this solvent are to be
introduced into waste streams.
Furthermore, there are significant regulatory burdens placed on solvents such
as perchloroethylene by agencies such as the EPA, OSHA and DOT. Such
regulation results in increased costs to the user, which, in turn, are passed
to the
ultimate consumer. For example, filters that have been used in conventional
perchloroethylene dry cleaning systems must be disposed of in accordance with
hazardous waste or other environmental regulations. Certain other solvents
used in
--1-

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
dry cleaning, such as hydrocarbon solvents, are extremely flammable, resulting
in
greater occupational hazards to the user and increased costs to control their
use.
In addition, textiles that have been cleaned using conventional cleaning
methods are typically dried by circulating hot air through the textiles as
they are
tumbled in a drum. The solvent must have a relatively high vapor pressure and
low
boiling point to be used effectively in a system utilizing hot air drying. The
heat used
in drying may permanently set some stains in the textiles. Furthermore, the
drying
cycle adds significant time to the overall processing time. During the
conventional
drying process, moisture adsorbed on the textile fibers is often removed in
addition
to the solvent. This often results in the development of undesirable static
electricity
and shrinkage in the garments. Also, the textiles are subject to greater wear
due to
the need to tumble the textiles in hot air for a relatively long time.
Conventional
drying methods are inefficient and often leave excess residual solvent in the
textiles,
particularly in heavy textiles, components constructed of multiple fabric
layers, and
structural components of garments such as shoulder pads. This may result in
unpleasant odors and, in extreme cases, may cause irritation to the skin of
the
wearer. In addition to being time consuming and of limited efficiency,
conventional
drying results in significant loss of cleaning solvent in the form of fugitive
solvent
vapor. Finally, conventional hot air drying is an energy intensive process
that results
in relatively high utility costs and accelerated equipment wear.
Traditional cleaning systems may utilize distillation in conjunction with
filtration
and adsorption to remove soils dissolved and suspended in the cleaning
solvent.
The filters and adsorptive materials become saturated with solvent, therefore,
disposal of some filter waste is regulated by state or federal laws. Solvent
evaporation especially during the drying cycle is one of the main sources of
solvent
loss in conventional systems. Reducing solvent loss improves the environmental
and economic aspects of cleaning substrates using cleaning solvents. It is
therefore
advantageous to provide a method and system for cleaning substrates that
utilizes a
solvent having less adverse attributes than those solvents currently used and
that
reduces solvent losses.
--2-

CA 02388913 2002-04-15
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As an alternative to conventional cleaning solvents, pressurized fluid
solvents
or densified fluid solvents have been used for cleaning various substrates,
wherein
densified fluids are widely understood to encompass gases that are pressurized
to
either subcritical or supercritical conditions so as to achieve a liquid or a
supercritical
fluid having a density approaching that of a liquid. In particular, some
patents have
disclosed the use of a solvent such as carbon dioxide that is maintained in a
liquid
state or either a subcritical or supercritical condition for cleaning such
substrates as
textiles, as well as other flexible, precision, delicate, or porous structures
that are
sensitive to soluble and insoluble contaminants.
For example, U.S. Patent No. 5,279,615 discloses a process for cleaning
textiles using densified carbon dioxide in combination with a non-polar
cleaning
adjunct. The preferred adjuncts are paraffin oils such as mineral oil or
petrolatum.
These substances are a mixture of alkanes including a portion of which are C,6
or
higher hydrocarbons. The process uses a heterogeneous cleaning system formed
by the combination of the adjunct which is applied to the textile prior to or
substantially at the same time as the application of the densified fluid.
According to
the data disclosed in Patent No. 5,279,615, the cleaning adjunct is not as
effective at
removing soil from fabric as conventional cleaning solvents or as the solvents
described for use in the present invention as disclosed below.
U.S. Patent No. 5,316,591 discloses a process for cleaning substrates using
liquid carbon dioxide or other liquefied gases below their critical
temperature. The
focus of this patent is on the use of any one of a number of means to effect
ultrasonic cavitation to enhance the cleaning performance of the liquid carbon
dioxide. In all of the disclosed embodiments, densified carbon dioxide is the
cleaning
medium. This patent does not describe the use of a solvent other than the
liquefied
gas for cleaning substrates. While the combination of ultrasonic cavitation
and liquid
carbon dioxide may be well suited to processing complex hardware and
substrates
containing extremely hazardous contaminants, this process is too costly for
the
regular cleaning of textile substrates. Furthermore, the use of ultrasonic
cavitation is
less effective for removing contaminants from textiles than it is for removing
contaminants from hard surfaces.
--3-

CA 02388913 2003-05-02
wo oin93ou ~ rcr~soor~s4~
U.S. Patent No. 5,377,705 discloses a process for cleaning precision parts
utilizing a liquefied pressurized gas in the supercritical state and an
environmentally
acceptable co-solvent. During this process, the parts to be cleaned are pre-
treated
with the co-solvent and then pieced in the cleaning vessel. Afterwards, the
contaminants and co-solvent are removed from the parts by circulating a
pressurized
gas in its supercritical state through the vessel. Redeposition of co-solvent
and
contaminants is controlled by the amount of pressurized gas that is pumped
through
the vessel. Co-solvents specified for use in conjunction with the cleaning
solvent
include aliphatics, terpenes, acetone, laminines, isopropyl alcohol, Axarel
(DuPont),
Petroferm Petrofenn, Inc.), kerosene, and Isopar-m (Exxon). During the
cleaning
process, the cleaning solvent (supercritical carbon dioxide) flows through a
vessel
containing the parts to be treated, through a filter or filters and directly
to a separator
in which the solvent is evaporated and recondensed. The disclosed co-solvents
for
use in this patent have high evaporation rates and low flash points. The use
of such
co-solvents results in high solvent losses, and high fire risks. Furthermore,
many of
the co-solvents are not compatible with common dyes and fibers used in textile
manufacture. Also, the use of supercritical carbon dioxide necessitates the
use of
more expensive equipment.
U.S. Patent No. 5,417,768 discloses a process for precision parts cleaning
using a two-solvent system. One solvent can be liquid at room temperature and
pressure while the second solvent can be supercritical carbon dioxide. The
objectives of this invention include using two or more solvents with minimal
mixing of
the solvents and to incorporate ultrasonic cavitation in such a way as to
prevent the
ultrasonic transducers from coming in contact with the first-mentioned
solvent. An
apparatus is described which consists of an open top vessel within a covered
pressurized vessel. The primary fluid is pumped into the open top vessel.
After
cleaning with the primary fluid, it is pumped from the open top vessel.
Pressurized
carbon dioxide is then pumped into the open top vessel and flushed through the
vessel until the level of contaminants within the verse! are reduced to the
desired
level. The co-solvents disclosed in this patent are the same solvents
specified in

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
U.S. Patent No. 5,377,705. Use of these solvents would introduce a high risk
of fire,
high levels of solvent loss and potential damage to a wide range of textiles.
U.S. Patent No. 5,888,250 discloses the use of a binary azeotrope comprised
of propylene glycol tertiary butyl ether and water as an environmentally
attractive
replacement for perchlorethylene in dry cleaning and degreasing processes.
While
the use of propylene glycol tertiary butyl ether is attractive from an
environmental
regulatory point of view, its use as disclosed in this invention is in a
conventional dry
cleaning process using conventional dry cleaning equipment and a conventional
evaporative hot air drying cycle. As a result, it has many of the same
disadvantages
as conventional dry cleaning processes described above.
Several of the pressurized fluid solvent cleaning methods described in the
above patents may lead to recontamination of the substrate and degradation of
cleaning efficiency because the contaminated solvent is not continuously
purified or
removed from the system. Furthermore, pressurized fluid solvent alone is not
as
effective at removing some types of soil as are conventional cleaning
solvents.
Consequently, pressurized fluid solvent cleaning methods require individual
treatment of stains and heavily soiled areas of textiles, which is a labor-
intensive
process. Furthermore, systems that utilize pressurized fluid solvents for
cleaning are
more expensive and complex to manufacture and maintain than conventional
cleaning systems. Finally, few if any conventional surfactants can be used
effectively in pressurized fluid solvents. The surfactants and additives that
can be
used in pressurized fluid solvent cleaning systems are much more expensive
than
those used in conventional cleaning systems.
There thus remains a need for an efficient and economic method and system
for cleaning substrates that incorporates the benefits of prior systems, and
minimizes
the difficulties encountered with each. There also remains a need for a method
and
system in which the hot air drying time is eliminated, or at least reduced,
thereby
reducing the wear on the substrate and preventing stains from being
permanently set
on the substrate.
--5-

CA 02388913 2002-04-15
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SUMMARY
In the present invention, certain types of organic solvents, such as glycol
ethers and, specifically, poly glycol ethers including dipropylene glycol n-
butyl ether,
tripropylene glycol n-butyl ether or tripropylene glycol methyl ether, or
similar
solvents or mixtures of such solvents are used. Any type of organic solvent
that falls
within the chemical formulae disclosed hereinafter may be used. However,
unlike
conventional cleaning systems, in the present invention, a conventional drying
cycle
is not necessary. Instead, the system utilizes the solubility of the organic
solvent in
pressurized fluid solvents, as well as the physical properties of pressurized
fluid
solvents, to dry the substrate being cleaned.
As used herein, the term "pressurized fluid solvent" refers to both
pressurized
liquid solvents and densified fluid solvents. The term "pressurized liquid
solvent" as
used herein refers to solvents that are preferably liquid at between
approximately
600 and 1050 pounds per square inch and between approximately 5 and 30 degrees
Celsius, but are gas at atmospheric pressure and room temperature. The term
"densified fluid solvent" as used herein refers to a gas or gas mixture that
is
compressed to either subcritical or supercritical conditions so as to achieve
either a
liquid or a supercritical fluid having density approaching that of a liquid.
Preferably,
the pressurized fluid solvent used in the present invention is an inorganic
substance
such as carbon dioxide, xenon, nitrous oxide, or sulfur hexafluoride. Most
preferably, the pressurized fluid solvent is densified carbon dioxide.
The substrates are cleaned in a perforated drum within a vessel in a cleaning
cycle using an organic solvent. A perforated drum is preferred to allow for
free
interchange of solvent between the drum and vessel as well as to transport
soil from
the substrates to the filter. After substrates have been cleaned in the
perforated
drum, the organic solvent is extracted from the substrates by rotating the
cleaning
drum at high speed within the cleaning vessel in the same way conventional
solvents
are extracted from substrates in conventional cleaning machines. However,
instead
of proceeding to a conventional evaporative hot air drying cycle, the
substrates are
immersed in pressurized fluid solvent to extract the residual organic solvent
from the
substrates. This is possible because the organic solvent is soluble in the
pressurized
--6-

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
fluid solvent. After the substrates are immersed in pressurized fluid solvent,
which
may also serve as a cleaning solvent, the pressurized fluid solvent is
transferred
from the drum. Finally, the vessel is de-pressurized to atmospheric pressure
to
evaporate any remaining pressurized fluid solvent, yielding clean, solvent-
free
substrates.
Glycol ethers, specifically poly glycol ethers, used in the present invention
tend to be soluble in pressurized fluid solvents such as supercritical or
subcritical
carbon dioxide so that a conventional hot air drying cycle is not necessary.
The
types of poly glycol ethers used in conventional cleaning systems must have a
reasonably high vapor pressure and a low boiling point because they must be
removed from the substrates by evaporation in a stream of hot air. Flowever,
solvents, particularly non-halogenated solvents, that have a high vapor
pressure and
a low boiling point generally also have a low flash point. From a safety
standpoint,
organic solvents used in cleaning substrates should have a flash point that is
as high
as possible, or preferably, it should have no flash point. By eliminating the
conventional hot air evaporative drying process, a wide range of solvents can
be
used in the present invention that have much lower evaporation rates, higher
boiling
points and higher flash points than those used in conventional cleaning
systems.
Thus, the cleaning system described herein utilizes solvents that are less
regulated and less combustible, and that efficiently remove different soil
types
typically deposited on textiles through normal use. The cleaning system
reduces
solvent consumption and waste generation as compared to conventional dry
cleaning systems. Machine and operating costs are reduced as compared to
currently used pressurized fluid solvent systems, and conventional additives
may be
used in the cleaning system.
Furthermore, one of the main sources of solvent loss from conventional dry
cleaning systems, which occurs in the evaporative hot air drying step, is
eliminated
altogether. Because the conventional evaporative hot air drying process is
eliminated, there are no heat set stains on the substrates, risk of fire
and/or
explosion is reduced, the total cycle time is reduced, and residual solvent in
the
substrates is substantially reduced or eliminated. Substrates are also subject
to less
__7_

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
wear, less static electricity build-up and less shrinkage because there is no
need to
tumble the substrates in a stream of hot air to dry them.
While systems according to the present invention utilizing pressurized fluid
solvent to remove organic solvent can be constructed as wholly new systems,
existing conventional solvent systems can also be converted to utilize the
present
invention. An existing conventional solvent system can be used to clean
substrates
with organic solvent, and an additional pressurized chamber for drying
substrates
with pressurized fluid solvent can be added to the existing system.
Therefore, according to the present invention, textiles are cleaned by placing
the textiles to be cleaned into a cleaning drum within a cleaning vessel,
adding an
organic solvent to the cleaning vessel, cleaning the textiles with the organic
solvent,
removing a portion of the organic solvent from the cleaning vessel, rotating
the
cleaning drum to extract a portion of the organic solvent from the textiles,
placing the
textiles into a drying drum within a pressurizable drying vessel, adding a
pressurized
fluid solvent to the drying vessel, removing a portion of the pressurized
fluid solvent
from the drying vessel, rotating the drying drum to extract a portion of the
pressurized fluid solvent from the textiles, depressurizing the drying vessel
to
remove the remainder of the pressurized fluid solvent by evaporation, and
removing
the textiles from the depressurized vessel.
These and other features and advantages of the invention will be apparent
upon consideration of the following detailed description of the presently
preferred
embodiment of the invention, taken in conjunction with the claims and appended
drawings, as well as will be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a cleaning system utilizing separate vessels for
cleaning and drying.
FIG. 2 is a block diagram of a cleaning system utilizing a single vessel for
cleaning and drying.
__g_

CA 02388913 2002-04-15
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DETAILED DESCRIPTION
Reference will now be made in detail to embodiments of the invention,
examples of which are illustrated in the accompanying drawings. The steps of
each
method for cleaning and drying a substrate will be described in conjunction
with the
detailed description of the system.
The methods and systems presented herein may be used for cleaning a
variety of substrates. The present invention is particularly suited for
cleaning
substrates such as textiles, as well as other flexible, precision, delicate,
or porous
structures that are sensitive to soluble and insoluble contaminants. The term
"textile"
is inclusive of, but not limited to, woven or non-woven materials, as well as
articles
therefrom. Textiles include, but are not limited to, fabrics, articles of
clothing,
protective covers, carpets, upholstery, furniture and window treatments. For
purposes of explanation and illustration, and not limitation, exemplary
embodiments
of a system for cleaning textiles in accordance with the invention are shown
in FIGS.
1 and 2.
As noted above, the pressurized fluid solvent used in the present invention is
either a pressurized liquid solvent or a densified fluid solvent. Although a
variety of
solvents may be used, it is preferred that an inorganic substance such as
carbon
dioxide, xenon, nitrous oxide, or sulfur hexafluoride, be used as the
pressurized fluid
solvent. For cost and environmental reasons, liquid, supercritical, or
subcritical
carbon dioxide is the preferred pressurized fluid solvent.
Furthermore, to maintain the pressurized fluid solvent in the appropriate
fluid
state, the internal temperature and pressure of the system must be
appropriately
controlled relative to the critical temperature and pressure of the
pressurized fluid
solvent. For example, the critical temperature and pressure of carbon dioxide
is
approximately 31 degrees Celsius and approximately 73 atmospheres,
respectively.
The temperature may be established and regulated in a conventional manner,
such
as by using a heat exchanger in combination with a thermocouple or similar
regulator
to control temperature. Likewise, pressurization of the system may be
performed
using a pressure regulator and a pump and/or compressor in combination with a
__g_

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
pressure gauge. These components are conventional and are not shown in FIGS.1
and 2 as placement and operation of these components are known in the art.
The system temperature and pressure may be monitored and controlled either
manually, or by a conventional automated controller (which may include, for
example, an appropriately programmed computer or appropriately constructed
microchip) that receives signals from the thermocouple and pressure gauge, and
then sends corresponding signals to the heat exchanger and pump and/or
compressor, respectively. Unless otherwise noted, the temperature and pressure
is
appropriately maintained throughout the system during operation. As such,
elements contained within the system are constructed of sufficient size and
material
to withstand the temperature, pressure, and flow parameters required for
operation,
and may be selected from, or designed using, any of a variety of presently
available
high pressure hardware.
In the present invention, the preferred organic solvent should have a flash
point of greater than 200°F to allow for increased safety and less
governmental
regulation, have a low evaporation rate to minimize fugitive emissions, be
able to
remove soils consisting of insoluble particulate soils and solvent soluble
oils and
greases, and prevent or reduce redeposition of soil onto the textiles being
cleaned.
Preferably, the organic solvent in the present invention is a glycol ether,
and
specifically a poly glycol ether such as dipropylene glycol n-butyl ether,
tripropylene
glycol n-butyl ether or tripropylene glycol methyl ether, or any combination
of two or
more of these. A description of the chemical formulae of the organic solvents
that
can be used in the cleaning processes of the invention follows. As used
herein,
elemental designations are the same as used by one of skill in the art. For
example,
as used herein, H designates hydrogen, O designated oxygen, C designates
carbon,
S designates sulfur, Si designates silicon, CH3 designates methyl, CH2CH3
designates ethyl, and R is a variable that designates a chemical structure as
described further herein.
In one embodiment of the invention, the organic solvent of the invention is
composed, in part, of a glycol ether having a structure of:
--10-

CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
R, H RZ H R3 H
H-( O-C-C )X-( O-C-C )y- ( O-C-C )Z-O-R'
H H H H H H
Generaf Chemical Structure A
A complete description of the glycol ether compounds that fall within the
generic
structure above and that fulfill the functional parameters of the invention
takes into
account some variability in the number of subunits identified by subscripts
"x", "y"
and "z". Subscripts "x", "y" and "z" can each be either zero or one and each
of their
values is independent of the value of the other two subscripts. That is, the
subscripts can have values different from each other. However, at least one of
"x",
"y" or "z" is one. Group R' has the structure of a straight-chain or branched
alkyl
group; that is a structure of C~H2~+,. Subscript value "j" is an integer
ranging from one
and the value of the difference calculated by 13-3(x+y+z). Because at least
one of
"x", "y" and "z" must always have the value of 1, "j" has a value ranging from
4 to 10.
Groups R,, RZ and R3 are each independently either H or CH3. The identities of
R,,
RZ and R3 are selected independent of each other; therefore, R, and R2 can be
H
while R3 is CH3. The types of glycol ether compounds that are encompassed by
this
chemical structure include, but are not limited to, mono and polyethylene and
propylene glycol aliphatic ethers.
Another group of organic solvent compositions that can be used in the
cleaning processes of the invention include solvents that can be described as
having
the chemical structure of:
R, R, RZ R$ R3 R9
H-( O-C-C )X-( O-C-C )y- ( O-C-C )Z-R'-R"
Ra R, o Rs R" Rs R, 2
General Chemical Structure B
--11-

CA 02388913 2002-04-15
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As with the organic solvents characterized by the Chemical Structure A, the
subscripts "x", "y" and "z" can each be either zero or one and each of their
values is
independent of the value of the other two subscripts. That is, the subscripts
can
have values different from each other. However, at least one of "x", "y" or
"z" is one.
Group R" has the structure of benzyl, phenyl, their fluorinated and partially
fluorinated analogues, C~H2~+,, or C~HaFb. Subscript value "j" is an integer
ranging
from one and the value of the difference calculated by 13-3(x+y+z). Subscript
values
"a" and "b" range from zero to 2j+1; and a+b=2j+1. Because at least one of
"x", "y"
and "z" must always have the value of 1, "j" has a value ranging from 4 to 10.
Group
R' can be any one of an O, S, carbonyl or ester groups. Lastly, R,_,2 have a
general
formula of CmH~Fp or CdHeF9. The subscripts "m", "n" and "p" have the values
described as follows: "m" is an integer ranging from zero to two; "n" and "p"
are
integers ranging from zero to five; and n+p=2m+1. The subscripts "d," "e" and
"g"
have the values described as follows: "d" is an integer ranging from zero to
two; "e"
and "g" are integers ranging from zero to five; and a+g=2d+1. The types of
glycol
ether compounds that are encompassed by this chemical structure include, but
are
not limited to, aromatic, aliphatic, and fluorinated and partially
fluorinated, aliphatic
and aromatic mono and poly glycol ethers and thioethers, and carbonyl and
ester
derivatives thereof.
The General Chemical Structure B described above can also be broken down
further into various subgroups, as is shown in Table 1 below.
TABLE
1
Sub- R,,3 R4~ R~-9 R,o.,z R R
group
B1 H or CH3 H H H O C~H2,;,
B2 H or CH3 H H H S, carbonylC~H2~"
or ester
B3 H CH3, or H H H O C~H2~~,
CZHS, and
at
least one
is
CHZCH3
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
TABLE
1
Sub- R,.3 R4~ R~_9 R,o.,z R' R,
group
B4 H, CH3, H H H S, carbonylC~Hz~"
or
CzHs, and or ester
at
least one
is
CHzCH3
B5 H H H H or CH3 O C Hz ;
and
at least
one is
CH3
B6 H H H H or CH3 S, carbonylC~Hz~"
and
at least or ester
one is
CH3
B7 H H H H CH3, or O C~H2._.
CZHS, and
at
least one
is
CH2CH3
B8 H H H H, CH3, S, carbonylC~Hz~"
or
CZHS, and or ester
at
least one
is
CHZCH3
B9 H, F, CH3, H or H or H Or F O C~HaFb
F F
CHZF, CHFz,
or CF3 and
at
least one
is
CH3, CHZF,
CHFz, or
CF3
B10 H F, CH3, H or H or H or F S, carbonyl,C~HaFb
F F
CHZF, CHFz, or ester
or CF3 and
at
least one
is
CH3, CHZF,
CHFz, or
CF3
B11 CmH~FP and H or H or H or F O C~HaFb
at F F
least one
is
CzH"FP
B12 CmH~Fp and H or H or H or F S, carbonylC~HaFb
at F F
least one or ester
is
CZH"FP
1 B13 H Or F H Or H Or H, F CH3, O C~HaFS
~ F F
CHZF, CHFz
or
CF3 and
at
least one
is
CH3, CHZF,
CHFz or
CF3
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CA 02388913 2002-04-15
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TABLE
1
Sub- R,.3 R4.~ R,.9 R,o-,2 R R
group
B14 H or F H or H or H, F, CH3, S, carbonylC~HaFb
F F
CHZF, CHFz or ester
or
CF3 and
at
least one
is
CH3, CHZF,
CHFZ or
CF3
B15 C",H~FP H Or H Or CdHeF9 O C~HaFb
F F
B16 CmH~FP H Or H Or CdHeF9 S, Carbonyl,C~HaFb
F F
or ester
B17 H, CH3, H H H O benzyl or
or phenyl
CZHS, and
at
least one
is
CHZCH3
B18 H, CH3, H H H S, carbonylbenzyl or
or phenyl
C2H5, and or ester
at
least one
is
CHzCH3
B19 H H H H or CH3 O benzyl or
and phenyl
at least
one is
CH3
B20 H H H H or CH3 S, carbonylbenzyl or
and phenyl
at least or ester
one is
CH3
B21 H H H H, CH3, O benzyl or
or phenyl
C2H5, and
at
least one
is
CH2CH3
B22 H H H H, CH3, S, carbonylbenzyl or
or phenyl
CzHs, and or ester
at
least one
is
CH2CH3
B23 CmH~FP H or H or H or F O benzyl, phenyl,
and at F F
least one or fluorinated
is or
CzH~FP partially
fluorinated
benzyl or
phenyl
B24 CmH~Fp H or H or H or F S, carbonylbenzyl, phenyl,
and at F F
least one or ester or fluorinated
is or
CZH"Fp partially
fluorinated
benzyl or
phenyl
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TABLE
1
Sub- R,_3 R4~ R,_s R,o-,2 R' R
group
B25 H or F H or H or H, F, CH3, O benzyl, phenyl
F F
CHzF, CHFZ or fluorinated
or or
CF3 and partially
at
least one fluorinated
is
CH3, CHZF, benzyl or
phenyl
CHFZ or
CF3
B26 H or F H or H or H, F, CH3, S, carbonylbenzyl, phenyl,
F F
CHZF, CHFz or ester or fluorinated
or or
CF3 and partially
at
least one fluorinated
is
CH3, CH2F, benzyl or
phenyl
CHFZ or
CF3
B27 H or F H or H or CmH~FP and O benzyl, phenyl,
F F at
least one or fluorinated
is or
CZH"FP partially
fluorinated
benzyl or
phenyl
B28 H or F H or H or CmH~Fp and S, carbonylbenzyl, phenyl,
F F at
least one or ester or fluorinated
is or
CzH~FP partially
fluorinated
benzyl or
phenyl
B29 CmH~FP H or H or CdHeF9 O benzyl, phenyl,
F F
or fluorinated
or
partially
fluorinated
benzyl or
phenyl
B30 CmH~FP H or H or CdHeF9 S, carbonylbenzyl, phenyl,
F F
or ester or fluorinated
or
partially
fluorinated
benzyl or
phenyl
In each of the groups described in Table 1 above, R,_,2 are grouped together
as R,_3,
R4~, R,_9, and R,o_,2 for ease of description. Where the individual components
of a
group can be different elements, the elements are described in the chart in
the
alternative. For example, R,_3 may be described as "H or F." In a given
solvent
compound with this description, each of R,, RZ and R3 may be H or each of R,,
RZ
and R3 may be F. Alternatively, R, and R2 may be H while R3 is F, and so forth
with
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the various combinations of "H" and "F". This is the same throughout the
Tables in
this specification.
Another group of organic solvent compositions that can be used in the
cleaning processes of the invention include solvents that can be described as
having
the chemical structure of:
R, R, Rz R8 R3 R9
Rw-( C-C-C )x-( G-C-C )Y- ( C-C-C )Z-R'-R"
R4 R,o Rs R" Rs R,2
General Chemical Structure C
In General Chemical Structure C, subscripts "x", "y" and "z" each have a value
of
either zero or one, but at least one of "x", "y" and "z" has a value of one.
Group R"
has a structure of C~H2~+, or C~H~F~ and group R"' has a structure of CkH2k+,
or CkH~Fs.
The values of subscripts "j" and "k" are integers ranging from one and the
value of
13-3(x+y+z). Therefore, subscripts "j" and "k" can have integer values ranging
from
one and a maximum value of 10 (if two of "x", "y" and "z" are zero). Further,
the sum,
j+k is an integer ranging from two and the value of 13-3(x+y+z). The
subscripts "u"
and "v" are integers ranging from zero to 2j+1; and a+v=2j+1. The subscripts
"r" and
"s" are integers ranging from zero to 2k+1; and r+s=2k+1.
In further defining General Chemical Structure C, groups R,_3 and R,o_,2 can
be hydrogen ("H"), fluorine ("F"), methyl ("CH3"), ethyl ("CH2CH3"), or
partially or fully
fluorinated methyl or ethyl groups. Each one of R,_3 and R,o_,2 are selected
independently of each other so as to achieve various combinations of the above
as
contemplated by the invention. Generally, R,_3 have the formula of CmH~FP. The
subscripts "m", "n" and "p" have the values described as follows: "m" is an
integer
ranging from zero to two; "n" and "p" are integers ranging from zero to five;
and
n+p=2m+1. Additionally, groups R4_9 can each be hydrogen, fluorine or methyl
groups. As with the other groups, the identity of each of R4_9 is selected
independent
of the identity of the other groups. Finally, the identity of group R' in
General
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Chemical Structure C is either O, S, a carbonyl group or an ester group. Each
of the
solvent compounds characterized by General Chemical Structure C is suitable
for
use as an organic solvent in the cleaning processes of the invention. The
types of
glycol ether compounds that are encompassed by this chemical structure
include,
but are not limited to, aliphatic and fluorinated and partially fluorinated
aliphatic mono
and poly glycol diethers and ether thioethers and carbonyl and ester
derivatives
thereof.
The General Chemical Structure C described above can also be broken down
further into various subgroups, as is shown in Table 2 below.
TABLE
2
Sub- R,.3 R,~ R,_9 R,o.,2 R R R
group
C1 H or CH3 H H H O C~H2~~,CkHzk.,
C2 H or CH3 H H H S, carbonylC~H2~" CkHzk.,
or ester
C3 H, CH3, H H H O C~HZ~" CkHzk+,
or
CZHS and
at
least one
is
CHZCH3
C4 H, CH3, H H H S, carbonylC~H2~" CkH2k.,
or
CZHS and or ester
at
least one
is
CH2CH3
C5 H H H H or CH3 O C~H2~" CkHZk.,
and at
least
one is
CH3
C6 H H H H or CH3 S, carbonylC~H2~" CkH2k"
and at or ester
least
one is
CH3
C7 H H H H, CH3 O C~HZ~~,CkH2k"
or
CZHS and
at
least
one is
CHzCH3
C8 H H H H, CH3 S, carbonylC~H2~~,CkH2k+,
or
CzHS and or ester
at
least
one is
CHzCH3
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TABLE
2
Sub- R,., R4.~ R,.9 R,o_,Z R R R
group
C9 H, F, H or H or F H or F O C~H~F~CkH~Fs
CH3, F
CHzF,
CHF2,
or
CF3
C10 H, F, H or H or F H or F S, carbonylC~H~F~CkH,Fs
CH3, F
CHzF, or ester
CHF2,
or
C F,
C11 C",H~FP H Or H Or F H Or F O C~H~F~CkH'FS
and F
at least
one
is CzH~FP
C12 CmH~Fp H or H or F H or F S, carbonylC,H~F~CkH,Fs
and F
at least or este r
one
is CZH~Fp
C13 H or F H or H or F H, F, O C~H~F~CkH,Fs
F CH3,
CH2F,
CHFz
or CF3
and
at least
one
is CH3,
CHzF,
CHF2
or CF3
C14 H or F H or H or F H, F, S, carbonylC~H~F~CkH'FS
F CH3,
CHZF, or ester
CHFZ
or CF3
and
at least
one
is CH3,
CH2F,
CHFZ
or CF3
C15 H, F, H, F, H, F, C,~,H~FP O C~H~F~CkH,Fs
CH3, CH3, CH3, and
CHZF, CH2F, CH2F, at least
one
CHF2, CHF2, CHF2, is CZH"FP
or or or
CF3 CF3 CF3
C16 H, F, H, F, H, F, CmH"FP S, carbonylC~H~F~CkH,Fs
CH3, CH3, CH3, and
CHzF, CHZF, CHZF, at least or ester
one
CHF2, CHFz, CHF2, is CzH~Fp
or or or
CF3 CF3 CF3
In each of the groups described in Table 2 above, one or more of R,_,2 are
described
together. For example, R,_3 may be described as "H or CH3 independently." In a
given solvent compound with this description, each of R,, RZ and R3 may be H
or
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CA 02388913 2002-04-15
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each of R,, R2 and R3 may be CH3. Alternatively, R, and RZ may be H while R3
is
CH3, and so forth with the various combinations of "H" and "CH3".
In another embodiment of the processes of the invention, substrates are
cleaned with an organic solvent and the organic solvent is removed from the
substrates using a pressurized fluid solvent. The organic solvent can have a
structural formula as follows:
2 8 3 9
R'~-( O-C-C )X-( O-C-C )Y- ( O-C-C )Z-O-R"
Ra R,o Rs R" Rs R,z
General Chemical Structure D
In General Chemical Structure D, subscripts "x", "y" and "z" each have a value
of
either zero or one, but at least one of "x", "y" and "z" has a value of one.
Group R" is
either H or has one of the following structures:
CR",3 CR",3 CR",3
-Si-O-Si-CR"'3 or -Si-CR"'3
CR",3 CR",3 CR",3
where R"' is H, F or combinations of H and F and group R"' is either H or one
of the
following structures:
C R~3 C R"3 C R"3
CR"3-Si-O-Si- or CR''3-Si-
C R"3 C R"3 C R"3
where R" is H, F or combinations of H and F. Where R" is H or F, R"' is not H
or F.
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
Groups R"' and R" are either H or F groups or combinations of H and F.
Therefore, within a given R" or R"' group, the R"' groups and R" groups can be
both
hydrogens and fluorines; they are not limited to being only hydrogen or
fluorine. In
further defining General Chemical Structure D, groups R,_3 can be H, F, CH3,
CHzF,
CHFZ or CF3. Each one of R4_,2 is independently either H or F.
In another embodiment of the processes of the invention, substrates are
cleaned with an organic solvent and the organic solvent is removed from the
substrates using a pressurized fluid solvent. The organic solvent can have a
structural formula as follows:
R'
R-O-CxHzX-N
R"
General Chemical Structure E
In General Chemical Structure E, R' is:
Riv Riv
H~-( R"'-C-C )k
Riv Riv
and R" is:
Riv Riv
H -( R",-C-C )~
Riv Riv
Each R"' is O or N independently. Where R"' is O, j is 1. Where R"' is N, j is
2.
Each R'~ is independently H, CH3 or CHZCH3 and k and n are integers between
zero
and two inclusive. R is CyH2Y+~ and y is an integer between one and (12-
(3k+3n+x))
inclusive, and x is an integer between one and (12-(3k+y)), inclusive.
In another embodiment of the processes of the invention, substrates are
cleaned with an organic solvent and the organic solvent is removed from the
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CA 02388913 2002-04-15
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substrates using a pressurized fluid solvent. The organic solvent can have a
structural formula as follows:
Riv Riv
R-O-CxH2X-O-( C-C- R"' )k- H
Riv Riv
General Chemical Structure F
In General Chemical Structure F, R"' is O or R"' is NH. Each R"' is
independently H,
CH3 or CH2CH3 and k is an integer between zero and two inclusive. R is CYHZY+,
and
y is an integer between one and (12- (3k+x)) inclusive, and x is an integer
between
one and (12-(3k+y)), inclusive, and x+y is less than or equal to 12.
Referring now to FIG. 1, a block diagram of a cleaning system having
separate vessels for cleaning and drying textiles is shown. The cleaning
system 100
generally comprises a cleaning machine 102 having a cleaning vessel 110
operatively connected to, via one or more motor activated shafts (not shown),
a
perforated rotatable cleaning drum or wheel 112 within the cleaning vessel 110
with
an inlet 114 to the cleaning vessel 110 and an outlet 116 from the cleaning
vessel
110 through which cleaning fluids can pass. A drying machine 104 has a drying
vessel 120 capable of being pressurized. The pressurizable drying vessel 120
is
operatively connected to, via one or more motor activated shafts (not shown),
a
perforated rotatable drying drum or wheel 122 within the drying vessel 120
with an
inlet 124 to the drying vessel 120 and an outlet 126 from the drying vessel
120
through which pressurized fluid solvent can pass. The cleaning vessel 110 and
the
drying vessel 120 can either be parts of the same machine, or they can
comprise
separate machines. Furthermore, both the cleaning and drying steps of this
invention can be performed in the same vessel, as is described with respect to
FIG.
2 below.
An organic solvent tank 130 holds any suitable organic solvent, as previously
described, to be introduced to the cleaning vessel 110 through the inlet 114.
A
pressurized fluid solvent tank 132 holds pressurized fluid solvent to be added
to the
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pressurizable drying vessel 120 through the inlet 124. Filtration assembly 140
contains one or more filters that continuously remove contaminants from the
organic
solvent from the cleaning vessel 110 as cleaning occurs.
The components of the cleaning system 100 are connected with lines 150-
156, which transfer organic solvents and vaporized and pressurized fluid
solvents
between components of the system. The term "line" as used herein is understood
to
refer to a piping network or similar conduit capable of conveying fluid and,
for certain
purposes, is capable of being pressurized. The transfer of the organic
solvents and
vaporized and pressurized fluid solvents through the lines 150-156 is directed
by
valves 170-176 and pumps 190-193. While pumps 190-193 are shown in the
described embodiment, any method of transferring liquid and/or vapor between
components can be used, such as adding pressure to the component using a
compressor to force the liquid and/or vapor from the component.
The textiles are cleaned with an organic solvent such as those previously
described or mixtures thereof. The textiles may also be cleaned with a
combination
of organic solvent and pressurized fluid solvent, and this combination may be
in
varying proportions from about 50% by weight to 100% by weight of organic
solvent
and 0% by weight to 50% by weight of pressurized fluid solvent. In the
cleaning
process, the textiles are first sorted as necessary to place the textiles into
groups
suitable to be cleaned together. The textiles may then be spot treated as
necessary
to remove any stains that may not be removed during the cleaning process. The
textiles are then placed into the cleaning drum 112 of the cleaning system
100. It is
preferred that the cleaning drum 112 be perforated to allow for free
interchange of
solvent between the cleaning drum 112 and the cleaning vessel 110 as well as
to
transport soil from the textiles to the filtration assembly 140.
After the textiles are placed in the cleaning drum 112, an organic solvent
contained in the organic solvent tank 130 is added to the cleaning vessel 110
via line
152 by opening valve 171, closing valves 170, 172, 173 and 174, and activating
pump 190 to pump organic solvent through the inlet 114 of the cleaning vessel
110.
The organic solvent may contain one or more co-solvents, water, detergents, or
other additives to enhance the cleaning capability of the cleaning system 100.
--22-

CA 02388913 2003-05-02 '
WO O1t39306 PGTNSOOn8433
Alternatively, one or more additives may be added directly to the cleaning
vessel
110. Pressurized fluid solvent may also be added to the cleaning vessel 110
along
with the organic solvent to enhance cleaning. !Pressurized fluid solvent can
be
added to the cleaning vessel 110 via line 154 by opening valve 174, closing
valves
170, 171, 172, 173, and 175, and activating pump 192 to pump pressurized fluid
solvent through the inlet 114 of the cleaning vessel 110. Of course, if
pressurized
fluid solvent is included in the cleaning cycle, the cleaning vessel 110 will
need to be
pressurized in the same manner as the drying vessel i20, as discussed below.
When a sufficient amount of the organic solvent, or combination of organic
solvent and pressurized fluid solvent, is added to the cieaningwessel 110, the
motor
(not shown) is activated and the perforated cleaning drum 112 is agitated
andlor
rotated within cleaning vessel 110. touring this phase, the organic solvent is
continuously cycled through the filtration assembly 140 by opening valves 170
and
172, closing valves 171, 173 and 174, and activating pump 191. Filtration
assembly
140 may include one or more fine mesh filters to remove particulate
contaminants
from the organic solvent passing therethrough and may alternatively or in
addition
include one or more absorptive or adsorptive filters to remove water, dyes and
other
dissolved contaminants from the organic solvent. Exemplary configurations for
filter
assemblies that can be used to remove contaminants from either the organic
solvent
or the pressurized fluid solvent are described more fully in U.S. Application
Serial No.
08/994,583 "published ~s loo g~1~220~". As a result, the organic solvent is
pumped through outlet 11 fi, valve 172, line 151, filter assembly 140, line
150, valve
170 and re-enters the cleaning vessel 110 via inlet 114. This cycling
advantageously
removes contaminants. including particulate contaminants andlor soluble
contaminants, from the organic solvent and reintroduces filtered organic
solvent to
the cleaning vessel 110 and agitating or rotating cleaning drum 112. Through
this
process, contaminants are removed from the textiles. Of courses in the event
the
- cleaning vessel 110 is pressurized, this recirculation system will be
maintained at the
same pressureltemperature levels as those in cleaning vessel 11D.
After sufficient time has passed so that the desired level of contaminants is
removed from the textiles and organic solvent, the organic solvent is removed
from
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the cleaning drum 112 and cleaning vessel 110 by opening valve 173, closing
valves
170, 171, 172 and 174, and activating pump 191 to pump the organic solvent
through outlet 116 via line 153. The cleaning drum 112 is then rotated at a
high
speed, such as 150-800 rpm, to further remove organic solvent from the
textiles.
The cleaning drum 112 is preferably perforated so that, when the textiles are
rotated
in the cleaning drum 112 at a high speed, such as 150-800 rpm, the organic
solvent
can drain from the cleaning drum 112. Any organic solvent removed from the
textiles by rotating the cleaning drum 112 at high speed is also removed from
the
cleaning drum 112 in the manner described above. After the organic solvent is
removed from the cleaning drum 112, it can either be discarded or recovered
and
decontaminated for reuse using solvent recovery systems known in the art.
Furthermore, multiple cleaning cycles can be used if desired, with each
cleaning
cycle using the same organic solvent or different organic solvents. If
multiple
cleaning cycles are used, each cleaning cycle can occur in the same cleaning
vessel, or a separate cleaning vessel can be used for each cleaning cycle.
After a desired amount of the organic solvent is removed from the textiles by
rotating the cleaning drum 112 at high speed, the textiles are moved from the
cleaning drum 112 to the drying drum 122 within the drying vessel 120 in the
same
manner textiles are moved between machines in conventional cleaning systems.
In
an alternate embodiment, a single drum can be used in both the cleaning cycle
and
the drying cycle, so that, rather than transferring the textiles between the
cleaning
drum 112 and the drying drum 122, a single drum containing the textiles is
transferred between the cleaning vessel 110 and the drying vessel 120. If the
cleaning vessel 110 is pressurized during the cleaning cycle, it must be
depressurized before the textiles are removed. Once the textiles have been
placed
in the drying drum 122, pressurized fluid solvent, such as that contained in
the
carbon dioxide tank 132, is added to the drying vessel 120 via lines 154 and
155 by
opening valve 175, closing valves 174 and 176, and activating pump 192 to pump
pressurized fluid solvent through the inlet 124 of the drying vessel 120 via
lines 154
and 155. When pressurized fluid solvent is added to the drying vessel 120, the
organic solvent remaining on the textiles dissolves in the pressurized fluid
solvent.
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After a sufficient amount of pressurized fluid solvent is added so that the
desired level of organic solvent has been dissolved, the pressurized fluid
solvent and
organic solvent combination is removed from the drying vessel 120, and
therefore
also from the drying drum 122, by opening valve 176, closing valve 175 and
activating pump 193 to pump the pressurized fluid solvent and organic solvent
combination through outlet 126 via line 156. If desired, this process may be
repeated to remove additional organic solvent. The drying drum 122 is then
rotated
at a high speed, such as 150-800 rpm, to further remove the pressurized fluid
solvent and organic solvent combination from the textiles. The drying drum 122
is
preferably perforated so that, when the textiles are rotated in the drying
drum 122 at
a high speed, the pressurized fluid solvent and organic solvent combination
can
drain from the drying drum 122. Any pressurized fluid solvent and organic
solvent
combination removed from the textiles by spinning the drying drum 122 at high
speed is also pumped from the drying vessel 120 in the manner described above.
After the pressurized fluid solvent and organic solvent combination is removed
from
the drying vessel 120, it can either be discarded or separated and recovered
for
reuse with solvent recovery systems known in the art. Note that, while
preferred, it is
not necessary to include a high speed spin cycle to remove pressurized fluid
solvent
from the textiles.
After a desired amount of the pressurized fluid solvent is removed from the
textiles by rotating the drying drum 122, the drying vessel 120 is
depressurized over
a period of about 5-15 minutes. The depressurization of the drying vessel 120
vaporizes any remaining pressurized fluid solvent, leaving dry, solvent-free
textiles in
the drying drum 122. The pressurized fluid solvent that has been vaporized is
then
removed from the drying vessel 120 by opening valve 176, closing valve 175,
and
activating pump 193. As a result, the vaporized pressurized fluid solvent is
pumped
through the outlet 126, line 156 and valve 176, where it can then either be
vented to
the atmosphere or recovered and recompressed for reuse.
While the cleaning system 100 has been described as a complete system, an
existing conventional dry cleaning system may be converted for use in
accordance
with the present invention. To convert a conventional dry cleaning system, the
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CA 02388913 2002-04-15
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organic solvent described above is used to clean textiles in the conventional
system.
A separate pressurized vessel is added to the conventional system for drying
the
textiles with pressurized fluid solvent. Thus, the conventional system is
converted
for use with a pressurized fluid solvent. For example, the system in FIG. 1
could
represent such a converted system, wherein the components of the cleaning
machine 102 are conventional, and the pressurized fluid solvent tank 132 is
not in
communication with the cleaning vessel 100. In such a situation, the drying
machine
104 is the add-on part of the conventional cleaning machine.
Furthermore, while the system shown in FIG. 1 comprises a single cleaning
vessel, multiple cleaning vessels could be used, so that the textiles are
subjected to
multiple cleaning steps, with each cleaning step carried out in a different
cleaning
vessel using the same or different organic solvents in each step. The
description of
the single cleaning vessel is merely for purposes of description and should
not be
construed as limiting the scope of the invention.
Referring now to FIG. 2, a block diagram of an alternate embodiment of the
present invention, a cleaning system having a single chamber for cleaning and
drying the textiles, is shown. The cleaning system 200 generally comprises a
cleaning machine having a pressurizable vessel 210. The vessel 210 is
operatively
connected to, via one or more motor activated shafts (not shown), a perforated
rotatable drum or wheel 212 within the vessel 210 with an inlet 214 to the
vessel 210
and an outlet 216 from the vessel 210 through which dry cleaning fluids can
pass.
An organic solvent tank 220 holds any suitable organic solvent, such as those
described above, to be introduced to the vessel 210 through the inlet 214. A
pressurized fluid solvent tank 222 holds pressurized fluid solvent to be added
to the
vessel 210 through the inlet 214. Filtration assembly 224 contains one or more
filters that continuously remove contaminants from the organic solvent from
the
vessel 210 and drum 212 as cleaning occurs.
The components of the cleaning system 200 are connected with lines 230-234
that transfer organic solvents and vaporized and pressurized fluid solvent
between
components of the system. The term "line" as used herein is understood to
refer to a
piping network or similar conduit capable of conveying fluid and, for certain
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purposes, is capable of being pressurized. The transfer of the organic
solvents and
vaporized and pressurized fluid solvent through the lines 230-234 is directed
by
valves 250-254 and pumps 240-242. While pumps 240-242 are shown in the
described embodiment, any method of transferring liquid and/or vapor between
components can be used, such as adding pressure to the component using a
compressor to force the liquid and/or vapor from the component.
The textiles are cleaned with an organic solvent such as those previously
described. The textiles may also be cleaned with a combination of organic
solvent
and pressurized fluid solvent, and this combination may be in varying
proportions of
50-100% by weight organic solvent and 0-50% by weight pressurized fluid
solvent.
In the cleaning process, the textiles are first sorted as necessary to place
the textiles
into groups suitable to be cleaned together. The textiles may then be spot
treated as
necessary to remove any stains that may not be removed during the cleaning
process. The textiles are then placed into the drum 212 within the vessel 210
of the
cleaning system 200. It is preferred that the drum 212 be perforated to allow
for free
interchange of solvent between the drum 212 and the vessel 210 as well as to
transport soil from the textiles to the filtration assembly 224.
After the textiles are placed in the drum 212, an organic solvent contained in
the organic solvent tank 220 is added to the vessel 210 via line 231 by
opening valve
251, closing valves 250, 252, 253 and 254, and activating pump 242 to pump
organic solvent through the inlet 214 of the vessel 210. The organic solvent
may
contain one or more co-solvents, detergents, water, or other additives to
enhance
the cleaning capability of the cleaning system 200. Alternatively, one or more
additives may be added directly to the vessel. Pressurized fluid solvent may
also be
added to the vessel 210 along with the organic solvent to enhance cleaning.
The
pressurized fluid solvent is added to the vessel 210 via tine 230 by opening
valve
250, closing valves 251, 252, 253 and 254, and activating pump 240 to pump the
pressurized fluid solvent through the inlet 214 of the vessel 210.
When the desired amount of the organic solvent, or combination of organic
solvent and pressurized fluid solvent as described above, is added to the
vessel 210,
the motor (not shown) is activated and the drum 212 is agitated and/or
rotated.
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CA 02388913 2003-05-02
wo o1n930b pCT/US00/Z8433
During this phase, the organic solvent, as well as pressurized fluid solvent
if used in
combination, is continuously cycled through the filtration assembly 224 by
opening
valves 252 and 253, closing valves 250, 251 and 254, and activating pump 241.
Filtration assembly 224 msy include one or more fine mesh filters to remove
particulate contaminants from the organic solvent and pressurized fluid
solvent
passing therethraugh and may alternatively or in addition include one or more
absorptive or adsorptive filters to remove water, dyes, and other dissolved
contaminants from the organic solvent. Exemplary configurations for fitter
assemblies that can be used to remove contaminants from either the organic
solvent
or the pressurized fluid solvent are described more fully in U.S. Application
Serial No.
08/994,583 "publi.sYaed as w0 g~/ 3:z2a~'~. As a result, the organic solvent
is
pumped through outlet 216, valve 253, line 233, filter assembly 224, line 232,
valve
252 and reenters the vessel 210 via inlet 214. This cycling advantageously
removes
contaminants, including particulate contaminants and/or soluble contaminants,
from
the organic solvent and pressurized fluid solvent and reintroduces filtered
solvent to
the vessel 210. .Through this process, contaminants are removed from the
textiles.
After sufficient time has passed so that the desired level of contaminants is
removed from the textiles and solvents, the organic solvent is removed from
the
vessel 210 and drum 212 by opening valve 254, closing valves 250, 251, 252 and
253, and activating pump 241 to pump the organic solvent through outlet 216
and
line 234. !f pressurized fluid solvent is used in combination with organic
solvent, it
may be necessary to first separate the pressurued fluid solvent from the
organic
solvent. The organic solvent can then either be discarded or, preferably,
contaminants may be removed from the organic solvent and the organic solvent
recovered for further use. Contaminants may be removed from the organic
solvent
with solvent recovery systems known in the art. The drum 212 is then rotated
at a
high speed, such as 150-800 rpm, to further remove organic solvent from the
textiles. The drum 212 is preferably perforated so that, when the textiles are
rotated
in the drum 212 at a high speed, the organic solvent can drain from the
cleaning
drum 212. Any organic solvent removed from the textiles by rotating the drum
212 at
high speed can also either be discarded or recovered for further use.
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
After a desired amount of organic solvent is removed from the textiles by
rotating the drum 212, pressurized fluid solvent contained in the pressurized
fluid
tank 222 is added to the vessel 210 by opening valve 250, closing valves 251,
252,
253 and 254, and activating pump 240 to pump pressurized fluid solvent through
the
inlet 214 of the pressurizable vessel 210 via line 230. When pressurized fluid
solvent
is added to the vessel 210, organic solvent remaining on the textiles
dissolves in the
pressurized fluid solvent.
After a sufficient amount of pressurized fluid solvent is added so that the
desired level of organic solvent has been dissolved, the pressurized fluid
solvent and
organic solvent combination is removed from the vessel 210 by opening valve
254,
closing valves 250, 251, 252 and 253, and activating pump 241 to pump the
pressurized fluid solvent and organic solvent combination through outlet 216
and line
234. Note that pump 241 may actually require two pumps, one for pumping the
low
pressure organic solvent in the cleaning cycle and one for pumping the
pressurized
fluid solvent in the drying cycle.
The pressurized fluid solvent and organic solvent combination can then either
be discarded or the combination may be separated and the organic solvent and
pressurized fluid solvent separately recovered for further use. The drum 212
is then
rotated at a high speed, such as 150-800 rpm, to further remove pressurized
fluid
solvent and organic solvent combination from the textiles. Any pressurized
fluid
solvent and organic solvent combination removed from the textiles by spinning
the
drum 212 at high speed can also either be discarded or retained for further
use.
Note that, while preferred, it is not necessary to include a high speed spin
cycle to
remove pressurized fluid solvent from the textiles.
After a desired amount of the pressurized fluid solvent is removed from the
textiles by rotating the drum 212, the vessel 210 is depressurized over a
period of
about 5-15 minutes. The depressurization of the vessel 210 vaporizes the
pressurized fluid solvent, leaving dry, solvent-free textiles in the drum 212.
The
pressurized fluid solvent that has been vaporized is then removed from the
vessel
210 by opening valve 254, closing valves 250, 251, 252 and 253, and activating
pump 241 to pump the vaporized pressurized fluid solvent through outlet 216
and
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
line 234. Note that while a single pump is shown as pump 241, separate pumps
may
be necessary to pump organic solvent, pressurized fluid solvent and
pressurized fluid
solvent vapors, at pump 241. The remaining vaporized pressurized fluid solvent
can
then either be vented into the atmosphere or compressed back into pressurized
fluid
solvent for further use.
As discussed above, dipropylene glycol n-butyl ether, tripropylene glycol
n-butyl ether and tripropylene glycol methyl ether are the preferred organic
solvents
for use in the present invention, as shown in the test results below. Table 3
shows
results of detergency testing for each of a number of solvents that may be
suitable
for use in the present invention. Table 4 shows results of testing of drying
and
extraction of those solvents using densified carbon dioxide.
Detergency tests were performed using a number of different solvents without
detergents, co-solvents, or other additives. The solvents selected for testing
include
organic solvents and liquid carbon dioxide. Two aspects of detergency were
investigated - soil removal and soil redeposition. The former refers to the
ability of a
solvent to remove soil from a substrate while the latter refers to the ability
of a
solvent to prevent soil from being redeposited on a substrate during the
cleaning
process. Wascherei Forschungs Institute, Krefeld Germany ("WFK") standard
soiled
swatches that have been stained with a range of insoluble materials and WFK
white
cotton swatches, both obtained from TESTFABRICS, Inc., were used to evaluate
soil
removal and soil redeposition, respectively.
Soil removal and redeposition for each solvent was quantified using the Delta
Whiteness Index. This method entails measuring the Whiteness Index of each
swatch before and after processing. The Delta Whiteness Index is calculated by
subtracting the Whiteness Index of the swatch before processing from the
Whiteness
Index of the swatch after processing. The Whiteness Index is a function of the
light
reflectance of the swatch and in this application is an indication of the
amount of soil
on the swatch. More soil results in a lower light reflectance and Whiteness
Index for
the swatch. The Whiteness indices were measured using a reflectometer
manufactured by Hunter Laboratories.
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~CA 02388913 2003-05-02 pC.h~SOQl~8433
TM
Organic solvent testing was carried out in a Launder-Ometer while the
densified carbon dioxide testing was carried out in a Parr Bomb. After
measuring
their Whiteness Indices, two WFK standard soil swatches and two WFK white
cotton
swatches were placed in a Launder-C9meter cup with 25 stainless steel ball
bearings
and 150 mL of the solvent of interest. The cup was then sealed, placed in the
Launder-Ometer and agitated for a specified length of time. Afterwards, the
swatches were removed and placed in a Parr Bomb equipped with a mesh basket.
Approximately 1.5 liters of liquid carbon dioxide between 5°C and
25°C and 570 psig
and 830 psig was transferred to the Parr Bomb. After several minutes the Parr
Bomb was vented and the dry swatches removed and allowed. to reach room
temperature. Testing of densil'~ed carbon dioxide was carried out by placing
the
swatches in a Parr Bomb, transferring liquid carbon dioxide at 20°C and
830 psig to
the Parr Bomb. The swatches were fastened to a wire frame attached to a
rotatable
shaft to enable the swatches to be agitated while immersed in the liquid
carbon
dioxide. The Whiteness Index of the processed swatches was determined using
the
reflectometer. The two Delta Whiteness Indices obtained for each pair of
swatches
were averaged. The results are presented in Table 3.
Because the Delta Whiteness Index is calculated by subtracting the
Whiteness Index of a swatch before processing from the Whiteness Index value
after
processing, a positive Delta Whiteness Index indicates that there was an
increase in
Whiteness index as a result of processing. In practical terms, this means that
soil
was removed during proce;~sing. In fact, the higher the Delta Whiteness Value,
the
more soil was removed from the swatch during processing. Each of the organic
solvents tested exhibited significant soil removal. Densified carbon dioxide
alone, on
the other hand, exhibited no soil removal. The WFK white cotton swatches
exhibited
a decrease it! Delta Whiteness Indices indicating that the soil was deposited
on the
swatches during the cleaning process. Therefore, a "less negative" Delta
Whiteness
Index suggests that less soil was redeposited. It should be noted that the
seemingly
excellent result obtained for densified carban dioxide is an anomaly and
resulted
from the fact that essentially no soil removal took place and therefore
essentially no
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
soil was present in the solvent which could be deposited on the swatch. The
organic
solvents on the other hand, exhibited good soil redeposition results.
TABLE 3
Cleaning Time Delta Whiteness
Values
Solvent (minutes)
Insoluble Insoluble
Soil Soil
Removal Redeposition
Densified Carbon Dioxide20 0.00 -0.54
(at 20C
and 830 psig)
Ethylene Glycol Ethyl 12 13.87 -5.10
Ether
Ethylene Glycol Ethyl 12 16.10 -11.40
Ether
Acetate
Diethylene Glycol Butyl12 12.80 -5.11
Ether
Propylene Glycol t-butyl12 14.35 -13.50
Ether
Dipropylene Glycol Methyl20 11.84 -5.64
Ether
Tripropylene Glycol 12 13.48 -5.60
Methyl Ether
Dipropylene Glycol n-Butyl12 13.97 -6.22
Ether
Dipropylene Glycol n-Propyl12 13.15 -7.50
Ether
Tripropylene Glycol 12 13.24 -4.35
n-Butyl Ether
To evaluate the ability of densified carbon dioxide to extract organic solvent
from a substrate, WFK white cotton swatches were used. One swatch was weighed
dry and then immersed in an organic solvent sample. Excess solvent was removed
from the swatch using a ringer manufactured by Atlas Electric Devices Company.
The damp swatch was re-weighed to determine the amount of solvent retained in
the
fabric. After placing the damp swatch in a Parr Bomb densified carbon dioxide
was
transferred to the Parr Bomb. The temperature and pressure of the densified
carbon
dioxide for all of the trials ranged from 5°C to 20°C and from
570 psig - 830 psig.
After five minutes the Parr Bomb was vented and the swatch removed. The swatch
was next subjected to Soxhlet extraction using methylene chloride for a
minimum of
two hours. This apparatus enables the swatch to be continuously extracted to
remove the organic solvent from the swatch. After determining the
concentration of
the organic solvent in the extract using gas chromatography, the amount of
organic
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
solvent remaining on the swatch after exposure to densified carbon dioxide was
calculated by multiplying the concentration of the organic solvent in the
extract by the
volume of the extract. A different swatch was used for each of the tests. The
results
of these tests are included in Table 4. As the results indicate, the
extraction process
using densified carbon dioxide is extremely effective.
TABLE-4
Weight Weight of Percentage
of Solvent by
on Test
Solvent Swatch Densified Weight of
(grams)
Carbon DioxideSolvent
Before After Used Removed from
ExtractionExtraction(kilograms) Swatch
Ethylene Glycol 1.8718 0.0069 1.35 99.63
Ethyl
Ether
Ethylene Glycol 1.9017 0.0002 1.48 99.99
Ethyl
Ether Acetate
Diethylene Glycol 1.9548 0.0033 1.72 99.83
Butyl
Ether
Propylene Glycol 2.0927 0.0010 1.24 99.95
t-butyl
Ether
Dipropylene Glycol2.1209 0.0005 1.31 99.98
Methyl Ether
Tripropylene Glycol1.9910 0.0022 1.71 99.89
Methyl Ether
Dipropylene Glycol1.8005 0.0023 1.77 99.87
n-Butyl Ether
Dipropylene Glycol1.7096 0.0034 1.59 99.80
n-Butyl Ether
Dipropylene Glycol1.7651 0.0018 3.36 99.90
n-Butyl Ether
Dipropylene Glycol1.7958 0.0012 1.48 99.94
n-Propyl Ether
Tripropylene Glycol1.8670 0.0034 1.30 99.82
n-Butyl Ether
It is to be understood that a wide range of changes and modifications to the
embodiments described above will be apparent to those skilled in the art and
are
contemplated. It is, therefore, intended that the foregoing detailed
description be
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CA 02388913 2002-04-15
WO 01/29306 PCT/US00/28433
--34-
regarded as illustrative rather than limiting, and that it be understood that
it is the
following claims, including all equivalents, that are intended to define the
spirit and
scope of the invention.
--34-