Two-step cleaning or dewatering with siloxane azeotropes
AssigneeDow Corning Corporation
InventorsCheryl A. McCormack, Dwight E. Williams
Life of this patent
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Abstract
A process for cleaning or dewatering a surface in which there is applied to the surface a washing composition containing a volatile methyl siloxane such as hexamethyldisiloxane or octamethyltrisiloxane, and an agent for enhancing cleaning or dewatering such as a glycol ether or surface active agent. While the surface is still wet with the washing composition, it is rinsed with an azeotrope containing hexamethyldisiloxane or octamethyltrisiloxane, and 2-pentanol, 2-methyl -1-pentanol, 3-methyl-3-pentanol, 1-methoxy-2-propanol, 1-butoxy -2-propanol, 1-hexanol, n-propoxypropanol, or ethyl lactate. The surface is then dried or permitted to dry.
Claims22
A process for cleaning or dewatering a surface which comprises (A) applying to the surface a washing composition comprising a volatile methyl siloxane selected from the group consisting of hexamethyldisiloxane and octamethyltrisiloxane, and an agent for enhancing cleaning or dewatering selected from the group consisting of a non-volatile organic compound bearing at least one hydroxyl, ether, or carbonyl group, and a surface active agent;
- (B) while the surface is still wet with the washing composition, rinsing the surface with a rinsing composition comprising an azeotrope or an azeotrope-like composition containing as components a volatile methyl siloxane selected from the group consisting of hexamethyldisiloxane and octamethyltrisiloxane, and a compound selected from the group consisting of 2-pentanol, 2-methyl-1-pentanol, 3-methyl-3-pentanol, 1-methoxy-2-propanol, 1-butoxy-2-propanol, 1-hexanol, n-propoxypropanol, and ethyl lactate;
- and then (C) drying or permitting the surface to dry;
- the azeotrope being a composition that is azeotropic at a temperature within a range selected from the group consisting of 0.degree.-148.degree. C., 0.degree.-162.degree. C., and 12.degree.-108.degree. C., and including a minimum boiling point at 760 Torr;
- the azeotrope-like composition being a composition that includes all ratios of components that boil within one Centigrade degree of the minimum boiling point of the azeotrope at 760 Torr.
A process for cleaning or dewatering a surface which comprises (A) applying to the surface a washing composition comprising a volatile methyl siloxane and an agent for enhancing cleaning or dewatering;
- (B) while the surface is still wet with the washing composition, rinsing the surface with a rinsing composition comprising an azeotrope or an azeotrope-like composition containing as one of its components a volatile methyl siloxane;
- and (C) drying or permitting the surface to dry;
- the azeotrope being a composition that is azeotropic at a temperature within a range selected from the group consisting of 0.degree.-148.degree. C., 0.degree.-162.degree. C., and 12.degree.-108.degree. C., and including a minimum boiling point at 760 Torr;
- the azeotrope-like composition being a composition that includes all ratios of components that boil within one Centigrade degree of the minimum boiling point of the azeotrope at 760 Torr.
A process for cleaning or dewatering a surface which comprises (A) applying to the surface a washing composition comprising a volatile methyl siloxane selected from the group consisting of hexamethyldisiloxane and octamethyltrisiloxane, and an agent for enhancing cleaning or dewatering selected from the group consisting of a non-volatile organic compound bearing at least one hydroxyl, ether, or carbonyl group, and a surface active agent;
- (B) while the surface is still wet with the washing composition, rinsing the surface with a rinsing composition comprising an azeotrope or an azeotrope-like composition containing as components a volatile methyl siloxane selected from the group consisting of hexamethyldisiloxane and octamethyltrisiloxane, and a compound selected from the group consisting of 2-pentanol, 2-methyl-1-pentanol, 3-methyl-3-pentanol, 1-methoxy-2-propanol, 1-butoxy-2-propanol, 1-hexanol, n-propoxypropanol, and ethyl lactate;
- and then (C) drying or permitting the surface to dry;
- the azeotrope being a composition that is azeotropic at a temperature within a range of 0.degree.-162.degree. C., and including a minimum boiling point at 760 Torr;
- the azeotrope-like composition being a composition that includes all ratios of components that boil within one Centigrade degree of the minimum boiling point of the azeotrope at 760 Torr.
A process for cleaning or dewatering a surface which comprises (A) applying to the surface a washing composition comprising a volatile methyl siloxane and an agent for enhancing cleaning or dewatering (B) while the surface is still wet with the washing composition, rinsing the surface with a rinsing composition comprising an azeotrope or an azeotrope-like composition containing as one of its components a volatile methyl siloxane;
- and (C) drying or permitting the surface to dry;
- the azeotrope being a composition that is azeotropic at a temperature within a range 0-162 .degree. C., and including a minimum boiling point at 760 Torr;
- the azeotrope-like composition being a composition that includes all ratios of components that boil within one Centigrade degree of the minimum boiling point of the azeotrope at 760 Torr.
Dependencies are inferred from the claim text.