What is claimed is:
1. An aqueous composition for pretreating metal substrates comprising:
a) at least one hydroxy functional cyclic compound present in an amount of at least about 500 ppm, said hydroxy functional cyclic compound selected from the group consisting of polyhydroxy phenolic compounds and heterocyclic nitrogen-containing compounds having hydroxy functionality;
b) phosphate ions;
c) at least one oxidizer-accelerator;
d) at least one Group IVB metal compound capable of converting to a metal oxide upon application to the metal substrate; and
e) water.
2. The composition of claim 1 wherein the hydroxy functional cyclic compound is selected from the group consisting of catechol, methylene-bridged poly(alkylphenols), coumaryl alcohol, coniferyl alcohol, hydroxyalkyl celluloses, lignin, tannin, sinapyl alcohol, and mixtures thereof.
3. The composition of claim 1 wherein the hydroxy functional cyclic compound is at least one tannin material.
4. The composition of claim 3 wherein the tannin material is selected from the group consisting of vegetable tannin, hydrolyzable tannin, condensable tannin, tannic acid, and mixtures thereof.
5. The composition of claim 4 wherein the tannin material is at least one of quebracho and mimosa tannins.
6. The composition of claim 1 wherein said hydroxy functional cyclic compound is present in an amount of about 500 ppm to about 2,500 ppm.
7. The composition of claim 1 wherein said phosphate ions are present in an amount of about 125 to about 300 ppm.
8. The composition of claim 1 wherein said oxidizer accelerator is present in an amount of about 10 to about 10,000 ppm.
9. The composition of claim 1 wherein said Group IVB metal compound is present in an amount of about 60 to about 600 ppm.
10. The composition of claim 1, having a pH within the range of about 3.5 to about 5.
11. The composition of claim 1 wherein said Group IVB metal compound is selected from the group consisting of hexafluorozirconic acid and hexafluorotitanic acid and their soluble salts.
12. The composition of claim 1, wherein said oxidizer-accelerator is selected from the group consisting of alkali metal chlorate, alkali metal bromate, alkali metal perchlorate, alkali metal chlorite, alkali metal nitrate, alkali metal nitrite, alkali metal perborate, ammonium chlorate, ammonium bromate, ammonium perchlorate, ammonium chlorite, ammonium nitrate, ammonium nitrite, ammonium perborate and mixtures thereof.
13. The composition of claim 1, wherein said oxidizer-accelerator is selected from the group consisting of halo-substituted benzene sulfonic acid, alkali metal salt of halo-substituted benzene sulfonic acid, ammonium salt of halo-substituted benzene sulfonic acid, nitro-substituted benzene sulfonic acid and ammonium salt of nitro-substituted benzene sulfonic acid.
14. The composition of claim 1, wherein said oxidizer-accelerator comprises a mixture of an alkali metal salt of meta-nitrobenzene sulfonic acid and at least one alkali metal salt selected from the group consisting of alkali metal chlorate and alkali metal nitrate.
15. The composition of claim 1, further comprising at least one disaccharide.
16. The composition of claim 15, wherein the disaccharide is selected from the group consisting of lactose and sucrose.
17. The composition of claim 11 wherein the disaccharide is present in an amount of 500 to 10,000 ppm.
18. A process for pretreating a metal substrate comprising contacting the substrate with an aqueous composition which comprises:
a) at least one hydroxy functional cyclic compound present in an amount of at least about 500 ppm, said hydroxy functional cyclic compound selected from the group consisting of hydroxy phenolic compounds and heterocyclic nitrogen-containing compounds having hydroxy functionality;
b) phosphate ions;
c) at least one oxidizer-accelerator;
d) at least one Group IVB metal compound capable of converting to a metal oxide upon application to the metal substrate; and
e) water.
19. The process of claim 18 wherein the metal substrate is selected from the group consisting of cold rolled steel, steel surface-treated with any of zinc metal, zinc compounds and zinc alloys; aluminum; aluminum alloys; zinc-aluminum alloys; aluminum plated steel; and aluminum alloy plated steel.
20. The process of claim 18 wherein the metal substrate is a combination of two or more metal substrates assembled together.
21. The process of claim 18 wherein the metal substrate is contacted with the aqueous composition by immersion.
22. The process of claim 18 wherein the metal substrate is contacted with the aqueous composition by spray application.
23. The process of claim 18 wherein the aqueous composition further comprises at least one disaccharide selected from the group consisting of lactose and sucrose.
24. The process of claim 18 wherein the aqueous composition is at ambient temperature.
25. The process of claim 18 further comprising the step of rinsing the metal substrate with an aqueous solution containing silane after contact with the aqueous composition.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An apparatus for separating ions, comprising:
a first electrode and a second electrode disposed one relative to the other in a spaced-apart facing arrangement for defining an analyzer region therebetween, the analyzer region including a first end and a second end and having a length extending between the first end and the second end;
a first gas inlet in fluid communication with the analyzer region, for providing a flow of a carrier gas of a first composition;
a second gas inlet in fluid communication with the analyzer region, for providing a flow of a carrier gas of a second composition; and,
a gas-flow directing element in fluid communication with the first gas inlet and in fluid communication with the second gas inlet, for receiving the flow of the carrier gas of the first composition and the flow of the carrier gas of the second composition, and for providing within a portion of the analyzer region a carrier gas flow having a composition that is non-uniform in space.
2. An apparatus according to claim 1, wherein during use the carrier gas flow within the portion of the analyzer region has substantially the first composition adjacent the first electrode and substantially the second composition adjacent the second electrode.
3. An apparatus according to claim 2, wherein during use the composition of the carrier gas flow varies across the analyzer region between the first electrode and the second electrode along a direction transverse to the length.
4. An apparatus according to claim 1, wherein the gas-flow directing element comprises a plurality of plate structures that are disposed in a stacked, spaced-apart arrangement.
5. An apparatus according to claim 1, wherein the first electrode and the second electrode each comprise a flat-plate electrode body.
6. An apparatus according to claim 1, wherein the gas-flow directing element comprises a diffuser that is disposed for restricting the flow of the carrier gas of the first composition and for restricting the flow of the carrier gas of the second composition.
7. An apparatus according to claim 1, comprising an electrical contact on one of the first electrode and the second electrode for receiving an electrical signal from a power supply for applying an asymmetric waveform voltage to the one of the first electrode and the second electrode, and for providing a direct current voltage difference between the first electrode and the second electrode.
8. An apparatus according to claim 1, wherein the analyzer region is a high field asymmetric waveform ion mobility spectrometry (FAIMS) analyzer region.
9. An apparatus according to claim 1, wherein the gas-flow directing element comprises a plurality of axially aligned, cylindrical plate structures that are disposed in a radially spaced-apart arrangement.
10. A method of separating ions, comprising:
providing a high field asymmetric waveform ion mobility spectrometry (FANS) analyzer region for separating ions;
providing a flow of a carrier gas within a portion of the FAIMS analyzer region, the flow of carrier gas having a composition that is non-uniform in space along a direction transverse to the flow of the carrier gas;
introducing ions into the FAIMS analyzer region;
providing electric field conditions within the FAIMS analyzer region for selectively transmitting a subset of the ions through the FAIMS analyzer region; and,
selectively transmitting the subset of ions along an average ion flow path through the FAIMS analyzer region.
11. A method according to claim 10, wherein providing a flow of carrier gas within a portion of the FAIMS analyzer region comprises providing a flow of a first gas and providing separately a flow of a second gas.
12. A method according to claim 11, wherein a composition of the flow of the first gas is different than a composition of the flow of the second gas.
13. A method according to claim 11, wherein providing a FAIMS analyzer region for separating ions comprises providing a first electrode surface and a second electrode surface that is spaced-apart from the first electrode surface and facing the first electrode surface, the first electrode surface substantially parallel to the second electrode surface.
14. A method according to claim 13, wherein providing a flow of the first gas comprises directing the first gas to flow adjacent and substantially parallel to the first electrode surface.
15. A method according to claim 14, wherein providing a flow of the second gas comprises directing the second gas to flow adjacent and substantially parallel to the second electrode surface.
16. A method according to claim 15, comprising directing the first gas flow and directing the second gas flow absent forming a carrier gas flow having a homogeneous composition.
17. A method according to claim 15, comprising directing the first gas flow and directing the second gas flow absent substantial mixing between the first gas flow and the second gas flow within the portion of the FAIMS analyzer region.
18. A method according to claim 15, comprising providing a gas flow directing element for affecting the first gas flow and the second gas flow prior to introduction into the portion of the analyzer region.
19. A method according to claim 15, comprising providing a gas flow directing element for providing substantially laminar flow of the first gas adjacent the first electrode surface and for providing substantially laminar flow of the second gas adjacent the second electrode surface.
20. A method according to claim 14, comprising providing a diffuser that is disposed between a gas source region and the portion of the analyzer region for restricting the flow of the first gas and for restricting the flow of the second gas.
21. A method according to claim 14, comprising disposing a diffuser between a gas source region and the portion of the analyzer region for equilibrating a pressure of the first gas and equilibrating a pressure of the second gas prior to introduction into the portion of the analyzer region.
22. A method according to claim 11, wherein the carrier gas composition that is non-uniform in space comprises a composition gradient extending between a portion that is enriched in the first gas proximate the first electrode surface and a portion that is enriched in the second gas proximate the second electrode surface.
23. A method according to claim 22, wherein a volume fraction of the first gas in the carrier gas decreases with increasing separation from the first electrode surface.
24. A method according to claim 10, wherein at least one of the flow of the first gas and the flow of the second gas is a flow of a single component gas.
25. A method according to claim 10, wherein at least one of the flow of the first gas and the flow of the second gas is a flow of a mixed gas.
26. A method according to claim 10, wherein selectively transmitting the subset of ions along an average ion flow path through the analyzer region comprises entraining the subset of ions in the flow of a carrier gas.
27. A method according to claim 10, wherein selectively transmitting the subset of ions along an average ion flow path through the analyzer region comprises providing an electric field gradient directed along a direction opposite the flow of carrier gas for causing the subset of ions to drift along the direction opposite the flow of carrier gas.