CA2448697C

CA2448697C - Method of making a passivated surface

Info

Publication number: CA2448697C
Application number: CA2448697A
Authority: CA
Inventors: Tracey Jacksier; Robert Benesch
Original assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Current assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Priority date: 2001-07-17
Filing date: 2002-07-15
Publication date: 2012-09-25
Anticipated expiration: 2022-07-15
Also published as: CA2448697A1; WO2003008664A2; WO2003008664A3; CN1529767A; DE60239339D1; KR20040030684A; US7794841B2; US8288161B2; US20050271544A1; AU2002317422A1; JP2004536227A; US20090120158A1; CN1223701C; EP1412551B1; EP1412551A2; ATE500350T1; US20110100088A1; US7837806B2

Abstract

Methods of passivating a metal surface are described, the methods comprising the step of i) exposing the metal surface to a silicon-containing passivation material; ii) evacuating the metal surface, iii) exposing the treated surface to a gas composition having a concentration of reactive gas that is greater than an intended reactive gas concentration of gas to be transported by the metal surface; iv) evacuating the metal surface to remove substantially all of the gas composition to enable maintenance of an increased shelf-life, low concentration reactive gas at an intended concentration; and v) exposing the metal surface to the reactive gas at the intended reactive gas concentration. Manufactured products, high stability fluids, and methods of making same are also described.

Description

METHOD OF MAKING A PASSIVATED SURFACE

Background of the Invention 1. Field of the Invention [0002] The invention is generally related to the field of gases and packaging and using same. More specifically, the invention relates to increased stability, low concentration reactive gases, products including same, and methods of making same.
2. Related Art [0003] Moisture is known to react with so-called "acid gases", such as hydrogen sulfide, carbonylsulfide, carbondisulfide and mercaptans (mercaptans are also referred to as thiols) to form a complex compound. (The term "acid gas"
is used herein to denote either gas phase, liquid phase, or mixture of gas and liquid phases, unless the phase is specifically mentioned.) [0004] One problem presents itself: if one is interested in producing acid gas standard compositions, in other words acid gases having a known concentration of one of these gases in a matrix or carrier fluid, then one must consider how to reduce or remove the moisture. Gas standards may have to have, and preferably do have, a long shelf life, since the standard acid gas may not be required immediately after production. A source of acid gas and/or matrix gas may contain a considerable amount of moisture. Therefore, the reduction or removal of moisture from the acid gas is of primary importance if the stability of the acid gas in the standard gas is to be maintained.

[0005] U.S. Pat. Nos. 5,255,445 and 5,480,677 describe processes for drying and passivating a metal surface to enhance the stability of gas mixtures containing one or more gaseous hydrides in low concentrations in contact therewith.
The process comprises purging gas in contact with the metal surface with inert gas to remove the purged gas, exposing the metal surface to an amount of a gaseous passivating or drying agent comprising an effective amount of a gaseous hydride of silicon, germanium, tin or lead and for a time sufficient to passivate the metal surface, and purging the gaseous passivating agent using inert gas. Optionally, an oxidizing agent is applied after the third step to stabilize the adsorbed stabilizing agent. The patent also mentions prior known processes, such as saturation passivation, where the container is subjected to several cycles of evacuating and filling with a much higher concentration of the same gaseous hydride, prior to being filled with the low concentration hydride mixture of interest. The two patents do not mention or describe processes to passivate containers adapted to store sulfur-containing gases, nor do they mention passivation techniques in which a first passivating agent is applied to the surface, followed by contacting with a higher concentration of the gas to be stored.

100061 Co-pending application serial number 10/157,467, filed on even date herewith, (serie 5718:
issued as United States Patent No. 6,752,852), describes the use of certain acid gas resistant molecular sieves to reduce or remove moisture from fluid compositions comprising a sulfur-containing compound. There is no disclosure or suggestion, however, for the passivation of containers adapted to contain the moisture-reduced compositions.
Such containers may have moisture adhered to the internal surfaces, which can and does react with acid gases, reducing their stability and shelf-life-[0007] Given the problem of moisture reacting with acid gases and reactive gases in general, it would be advantageous if passivation methods could be provided which increase the shelf-life during the storage of these compounds.
Summary of the invention (00081 In accordance with the present invention, methods of passivating internal surfaces of containers that have been cleaned are employed to increase the shelf-life of gas compositions, especially low concentration gas products. As used herein the term "shelf-life" means that time during which the initial concentration of a gas stored in a container is substantially maintained at the intended or desired concentration. In this context, the phrase "substantially maintained" means that for concentrations of about 1000 parts per billion (ppb), the concentration does not vary by more than +/-10 percent; for concentrations of about 500 ppb, the concentration does not vary by more than +/- 15 percent; for concentrations of about 100 ppb, the concentration does not vary by more than +/- 20 percent. "Low concentration' 'means gases having a concentration in another gas, such as inert gas, of 1000 ppb or less.

[0009] Gases which benefit for the, passivation techniques of the present invention include nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, and any acid gases except those that would react with a silicon-containing compound.

[0010] As used herein the term "acid gas" means sulfur-containing compounds, including carbon disulfide, carbonylsulfide, and compounds within formula (I):

Y-S-X (I) wherein S is sulfur, X and Y are the same or different and are independently selected from the group consisting of hydrogen, alkyl, aryl, oxygen, hydoxyl, amine, aminosilane, oxygen, and alcohol.
Examples of preferred sulfur-containing compounds within formula (I) include hydrogen sulfide, methylthiol, ethylthiol, n-propylthiol, i-propylthiol, benzylthiol, and the like.

[0011] A first aspect of the invention relates to a manufactured product comprising:
a) a container having an internal space and a passivated internal metal surface;
b) a composition comprising a reactive gas contained within the internal space and in contact with the passivated internal metal surface, the reactive gas having an intended concentration that is substantially maintained; and c) the passivated internal metal surface comprising:
1) the reaction product of a silicon-containing material and an oxygen-containing material (preferably selected from the group consisting of moisture, molecular oxygen, metal oxides, and mixtures thereof), and 2) an effective amount of the reactive gas, the effective amount being many times the intended concentration of reactive gas that is to be substantially maintained.

[00121 Preferred manufactured products of the invention are those wherein the reactive gas is selected from the group consisting of chlorine and an acid as selected from the group consisting of carbondisulfide, carbonylsulfide, and compounds within formula (I). Other preferred manufactured products include products wherein the passivated internal surface is a passivated metal.
Preferably the metal is selected from the group consisting of aluminum, aluminum alloys, steel, iron and combinations thereof. Yet other preferred manufactured products of the invention are those wherein the silicon-containing material is selected from the group consisting of compounds within the general formula (II):

SiR1R2R3R4 (II) wherein Rl, R2, R3, and R4 are the same or different and are independently selected from the group consisting of hydrogen, halogen, amine, alkyl, aryl, halogenated alkyl, and halogenated aryl; and manufactured products wherein the compound is silane or a methyl-containing silane, more preferably wherein the methyl-containing silane is selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane.

[00131 Preferred manufactured products of the invention are those wherein the composition comprises a reactive gas having a concentration of about 1000 ppb and that does not vary by more than +/- 10 percent; products wherein the composition comprises a reactive gas having a concentration of about 500 ppb and that does not vary by more than +/- 15 percent; products wherein the composition comprises a reactive gas having a concentration of about 100 ppb and that does not vary by more than +/- 20 percent;. Products wherein the composition comprises higher or lower concentration of reactive gas, and correspondingly larger or smaller variation in concentration, are considered within the invention.

[00141 Preferred manufactured products of the invention comprise only a single reactive gas with an inert gas like nitrogen, argon, helium, and the like. The composition may comprise a mixture of two or more reactive gases. Also, the balance of the fluid composition is, in some preferred embodiments, a hydrocarbon. For example, 5 ethylene on propylene.

[00151 A second aspect of the invention is a method of making a manufactured product of the invention, the method comprising the steps of:
i) exposing an internal metal surface of a container to a first fluid composition comprising a silicon-containing compound for a time sufficient to allow at least some of the silicon-containing compound to react with oxygen-containing compounds (preferably selected from the group consisting of moisture, molecular oxygen, metal oxides, and mixtures thereof) present to form a silicon-treated surface or, at least some of the internal metal surface, the silicon-containing compound selected from the group consisting of compounds within the general formula (II):

SiR'RZR3R4 (II) wherein RI, R2, R3, and R4 are the same or different and are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl;
ii) evacuating the container for a time sufficient to remove substantially all of the silicon-containing compound(s) that has not reacted with the oxygen-containing compound to form the silicon-treated surface;
iii) exposing the silicon-treated surface to a second fluid composition, the second fluid composition comprising a reactive gas having a concentration that is greater than an intended reactive gas concentration of the manufactured product;
iv) evacuating the container for a time sufficient to remove just enough of the second fluid composition to enable maintenance of an increased shelf-life, low concentration reactive gas at the intended concentration in the container; and v) filling the container with a third fluid composition having the intended reactive gas concentration for the manufactured product.

(00161 Preferred methods in this aspect of the invention are those wherein the silicon-containing compound is silane or a methyl-containing organosilane;

particularly those wherein the methyl-containing organosilane is selected from the group consisting of silane, methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane. Also preferred are methods wherein the second fluid composition has a concentration of reactive gas at least 10 times the intended reactive gas concentration of the manufactured product; methods wherein steps i) and ii) are repeated prior to step iii); methods wherein the metal surface is cleaned prior to step i); methods wherein the concentration of the silicon-containing compound used in step i) ranges from about 100 ppm to 100 percent; methods wherein during step i) the silicon-containing compound is heated to a temperature of not more than 74 C, and methods wherein during step iii) the second composition is heated to a temperature of not more than 74 C. Other preferred methods are those wherein the container is a gas cylinder having an attached cylinder valve, and the cylinder valve is removed prior to step i). After all the steps are completed, preferably at very high temperatures for steps i) and iii), the cylinder valve is reattached, and the process steps i) -v) are repeated, but steps i) and iii) take place at not more than 74 C.

[00181 A third aspect of the invention is a method of passivating a metal surface, the method comprising the steps of:
i) exposing the metal surface to a first composition comprising a silicon-containing compound for a time sufficient to allow at least some of the silicon-containing compound to react with oxygen-containing compounds present to form a silicon-treated surface on at least some of the metal surface, the silicon-containing compound selected from the group consisting of compounds within the general formula (II):
SiR1R2R3R4 (II) wherein Rl, R2, R3, and R4 are the same or different and are independently selected from the group consisting of hydrogen, halogen, amine, alkyl, aryl, halogenated alkyl, and halogenated aryl;
ii) evacuating the surface for a time sufficient to remove substantially all silicon-containing compound that has not reacted with the oxygen-containing compound to form the silicon-treated surface;

iii) exposing the silicon-treated surface to a second fluid composition, the second fluid composition comprising a reactive gas having a concentration that is greater than an intended reactive gas concentration to be in contact with the silicon-treated surface;
iv) evacuating the surface for a time sufficient to remove just enough of the second fluid composition to enable maintenance of a low concentration of reactive gas at an intended concentration; and v) exposing the metal treated surface to a third fluid composition having concentration of reactive gas at the intended reactive gas concentration.
[00191 Preferably, the metal surface is part of a pipe, piping manifold, tubing, tubing manifold, ton unit, tube trailer, tank trailer, cylinder, flow regulator, pressure regulator, valve, cylinder valve, or other pressure-reducing device.
The metal surface is preferably cleaned prior to step i) as disclosed further herein.

[00201 Further aspects and advantages of the invention will become apparent by reviewing the description of preferred embodiments that follow.

[0020a] In accordance with another aspect of the present invention, there is provided a manufactured product comprising a gas having an extended shelf-life, the product comprising:

a) a container having an internal space and a clean and passivated internal metal surface;
b) a composition comprising a reactive gas that is 1) contained within the internal space and in contact with the clean passivated internal metal surface, the reactive gas having a concentration that is substantially maintained at a concentration of 1000 ppb or less within a matrix gas; and 2) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, and acid gases, and 7a mixtures thereof, with the proviso that the reactive gas does not include acid gases that react with a silico-containing material; and a) wherein the clean and passivated internal metal surface comprises:
1) the reaction product of a silicon-containing material selected from the group consisting of compounds within the general formula:
SiR'R2R3R4 wherein R', R2, R3, R4 are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl and an oxygen-containing material, and 2) an effective amount of the reactive gas adsorbed on the reaction product by exposing the reaction product on the internal metal surface to the reactive gas having a concentration at least 10 times the concentration of the reactive gas being substantially maintained in step b), the amount of reactive gas having a concentration adsorbed thereon resulting from the previous exposure of the reaction product to the reactive gas before the evacuation of the reactive gas from the internal space and prior to filling the internal space with the composition.
[0020b] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein the oxygen-containing material is selected from the group consisting of H2O, N20, CO2, molecular oxygen, metal oxides, and mixtures thereof.

[0020c] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein the clean and passivated internal metal surface comprises:

a) a coating comprising SiO2, and b) an effective amount of the reactive gas adsorbed on the coating by exposing the internal metal surface to the reactive gas having a concentration at least 10 times 7b the concentration of the reactive gas being substantially maintained in step b), the amount of reactive gas having a concentration adsorbed thereon resulting from the previous exposure of the reaction product to the reactive gas before the evacuation of the reactive gas from the internal space and prior to filling the internal space with the composition.

[0020d] In accordance with another aspect of the present invention, there is provided the product of the present invention, wherein said internal metal surface is aluminum or an aluminum alloy, wherein the reactive gas comprises an acid gas and said acid gas is selected from the group consisting of carbondisulfide, carbonylsulfide, and compounds within formula (I):

Y-S-X (I) wherein S is sulfur, and X and Y are the same or different and are independently selected from the group consisting of hydrogen, alkyl, aryl, oxygen, hydroxyl, amino and aminosilane; wherein the concentration at which the reactive gas is being substantially maintained is 500 ppb or less; and wherein the concentration of the exposed reactive gas is at least 50,000 times the concentration of the reactive gas being substantially maintained in step b).

[0020e] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein said passivated internal surface is a passivated metal.

[0020f] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein said metal is selected from the group consisting of aluminum, aluminum alloys, steel, iron and combinations thereof.

7c [0020g] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein said silicon containing material is a methyl-containing silane.

[0020h] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein said methyl-containing silane is selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane.

[0020i] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein the composition has a reactive gas concentration of about 500 ppb and does not vary by more than +/-15 percent.

[0020j] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein the composition has a reactive gas concentration of about 100 ppb and does not vary by more than +/- 20 percent.

10020k] In accordance with another aspect of the present invention, there is provided the product of the present invention wherein the composition comprises a single reactive gas mixed with a matrix gas selected from the group consisting of an inert gas, a hydrocarbon gas, and mixtures thereof.

[00201] In accordance with another aspect of the present invention, there is provided a method of making the manufactured product of the present invention from a clean container, the method comprising the steps of:
i) exposing an internal metal surface of a container to a first fluid composition comprising a silicon-containing compound for a time sufficient to allow at least some of the silicon-containing compound to react with an oxygen-containing compound present to form a silicon-treated surface on at least some of the 7d internal metal surface, the silicon-containing compound selected from the group consisting of compounds within the general formula:

SiR'R2R3R4 wherein R1, R2, R3, and R4 are the same or different and are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl;

ii) evacuating the container for a time sufficient to remove substantially all silicon-containing compound that has not reacted with the oxygen-containing compound to form the silicon-treated surface;
iii) exposing the silicon-treated surface to a second fluid composition, the second fluid composition comprising a reactive gas:
a) having a concentration within a matrix gas that is at least 10 times the intended reactive gas concentration of the manufactured product; and b) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, and acid gases, and mixtures thereof, with the proviso that the reactive gas does not include acid gases that react with a silicon-containing material; and iv) evacuating the container for a time sufficient to remove substantially all of-the second fluid composition, thus forming said passivated internal metal surface in the container; and v) filling the container with a third fluid composition having the intended reactive gas concentration for the manufactured product.

[0020m] In accordance with another aspect of the present invention, there is provided there a method of the present invention wherein the silicon-containing compound is selected from the group consisting of silane and a methyl-containing silane.

[0020n] In accordance with another aspect of the present invention, there is provided there a method of the present invention wherein said methyl-containing silane is 7e selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane.

[00200] In accordance with another aspect of the present invention, there is provided there a method of the present invention wherein steps i) and ii) are repeated prior to step iii).

[0020p] In accordance with another aspect of the present invention, there is provided there a method of the present invention wherein the concentration of the silicon-containing compound used in step i) ranges from 100 ppm to 100 percent.

[0020q] In accordance with another aspect of the present invention, there is provided there a method of the present invention wherein during step i) the first fluid composition is heated to a temperature of not more than 74 C.

[0020x] In accordance with another aspect of the present invention, there is provided there a method of the present invention wherein during step iii) the second fluid composition is heated to a temperature of not more than 74 C.

[0020m] In accordance with another aspect of the present invention, there is provided there a method of making a device having a passivated metal surface, the method comprising the steps of.
i) exposing a metal surface to a silicon-containing compound selected from the group consisting of compounds within the general formula:
SiR'R2R3R4 wherein R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, halogen, amine, alkyl, aryl, halogenated alkyl, and halogenated aryl, for a time sufficient to form a silicon treated surface on at least some of the metal surface;

7f ii) evacuating the metal surface for a time sufficient to remove silicon-containing material that has not reacted with oxygen-containing compounds on the metal surface to form a silicon-treated surface;
iii) exposing the silicon-treated surface to a gas composition, the gas composition comprising a reactive gas::
a) having a concentration within a matrix gas that is at least 10 times the intended reactive gas concentration of gas to be contained in the device; and b) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, and acid gases, and mixtures thereof.
with the proviso that the reactive gas does not include acid gases that react with a silicon-containing material; and iv) evacuating the silicon-treated surface for a time sufficient to remove substantially all of said gas composition and thus forming a passivated metal surface.

10020n1 In accordance with another aspect of the present invention there is provided a manufactured product comprising a gas having an extended shelf-life, the product comprising:
a) a container having an internal space and a clean and passivated internal metal surface;
b) a composition comprising a reactive gas that is 1) contained within the internal space and in contact with the clean passivated internal metal surface, the reactive gas having a concentration that is substantially maintained at a concentration of 1000 ppb or less within a matrix gas; and 2) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, acid gases which are inert in relation to silicon-containing materials, and mixtures thereof; and c) wherein the clean and passivated internal metal surface comprises:
1) the reaction product of a silicon-containing material selected from the group consisting of compounds within the general formula:

7g SiR'R2R'R4 wherein R', R2, R3, R4 are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl and an oxygen-containing material selected from the group consisting of H2O, N20, CO2, molecular oxygen, metal oxides, and mixtures thereof., and 2) an effective amount of the reactive gas adsorbed on the reaction product by exposing the reaction product on the internal metal surface to the reactive gas having a concentration at least 10 times the concentration of the reactive gas being substantially maintained in step b), the amount of reactive gas having a concentration adsorbed thereon resulting from the previous exposure of the reaction product to the reactive gas before the evacuation. of the reactive gas from the internal space and prior to filling the internal space with the composition.

1002001 In accordance with another aspect of the present invention, there is provided a method of making the manufactured product of the present invention from a clean container, the method comprising the steps of.
i) exposing an internal metal surface of a container to a first fluid composition comprising a silicon-containing compound for a time sufficient to allow at least some of the silicon-containing compound to react with an oxygen-containing compound present to form a silicon-treated surface on at least some of the internal metal surface, the silicon-containing compound selected from the group consisting of compounds within the general formula:

SiR'R2R3R4 wherein R1, R2, R3, and R4 are the same or different and are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl and the oxygen-containing compound 7h selected from the group consisting of H2O, N20, CO2, molecular oxygen, metal oxides, and mixtures thereof;
ii) evacuating the container for a time sufficient to remove substantially all silicon-containing compound that has not reacted with the oxygen-containing compound to form the silicon-treated surface;
iii) exposing the silicon-treated surface to a second fluid composition, the second fluid composition comprising a reactive gas:
a) having a concentration within a matrix gas that is at least 10 times the intended reactive gas concentration of the manufactured product; and b) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, acid gases which are inert in relation to silicon-containing materials, and mixtures thereof; and iv) evacuating the container for a time sufficient to remove substantially all of-the second fluid composition, thus forming said passivated internal metal surface in the container; and v) filling the container with a third fluid composition having the intended reactive gas concentration for the manufactured product.

[0020p] In accordance with another aspect of the present invention, there is provided a method of making a device having a passivated metal surface, the method comprising the steps of:
i) exposing a metal surface to a silicon-containing compound selected from the group consisting of compounds within the general formula:

SiR'R2R'R4 wherein R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, halogen, amine, alkyl, aryl, halogenated alkyl, and halogenated aryl, for a time sufficient to form a silicon treated surface on at least some of the metal surface;

7i ii) evacuating the metal surface for a time sufficient to remove silicon-containing material that has not reacted with oxygen-containing compounds on the metal surface to form the silicon-treated surface, the oxygen-containing compounds selected from the group consisting of H2O, N20, CO2, molecular oxygen, metal oxides, and mixtures thereof;
iii) exposing the silicon-treated surface to a gas composition, the gas composition comprising a reactive (yas::
c) having a concentration within a matrix gas that is at least 10 times the intended reactive gas concentration of gas to be contained in the device; and d) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichlo.ride, acid gases which are inert in relation to silicon-containing materials, and mixtures thereof; and iv) evacuating the silicon-treated surface for a time sufficient to remove substantially all of said gas composition and thus forming a passivated metal surface.

Brief Description of the Drawing [0021] FIG. i is a logic diagram illustrating the methods of the invention [0022] FIG. 2 illustrates that a prior art process of "vacuum baking" an aluminum cylinder at 65 C to vacuum of 1 micrometer Hg for 3 days was not sufficient to provide stability of a 150 ppb H2S balance nitrogen mixture for a cylinder which was previously exposed to moisture;

[0023] FIG. 3 illustrates that a prior art process of passivation of a cylinder and valve after vacuum baking with a high concentration of the gas mixture to be prepared, which had also been used to extend shelf life of a high purity mixture, did not prove successful; and [0024] FIGs. 4 and 5 illustrate stability of gas products made in accordance with the invention.

Description of Preferred Embodiments [0025] While the following discussion focuses on a container which has a metal internal surface, the description is not limited thereto, and could apply to a piping or tubing system, a manifold, a gas cylinder having a cylinder valve, ton unit, and the like.

[0026] Silicon-containing compounds within the general formula (II) are known to react with oxygen-containing compounds, such as H2O, N20, C02, and the like, to produce Si02, especially when the silicon-containing compounds are in the gaseous or vapor state. This fact is taken advantage of in the practice of the various aspects of the invention. The reaction product of a silicon-containing compound and an oxygen-containing compound such as water forms an amorphous or crystalline glassy material on the surfaces on which it is deposited. The amorphous or crystalline glassy material may include aluminum silicide, if the container or surface being treated comprises aluminum. Although the deposited material is referred top herein as a "coating", it shall be readily understood that in fact the material may deposit non-uniformly, or not at-all on certain areas of the surface being treated. This coating then serves the function of deactivating a surface for the adsorption of molecules of the gas that is ultimately to be contained in the container or piping system at low concentration. In other words, the coating serves to decrease the number of reactive sites on the metal surface being treated. For simplicity, silicon-containing compounds within formula (II) shall be referred to as organosilanes, although their formal name under IUPAC convention may differ.

[0027] The reaction of an organosilane within general formula (II) with oxygen-containing materials such as water proceeds without catalyst at room temperature (25 C); however, it is preferred to carry out the reaction at moderately elevated temperatures, such as temperature ranging from 25 C up to 100 C, in order to produce the coatings in reasonable time. The pressure of the reaction of an organosilane with water vapor will generally also proceed at atmospheric pressure, however, the pressure in the container, or near the surface being treated, may either be in vacuum or above atmospheric pressure. This will of course depend on the rates of reaction of the organosilane with the oxygen-containing compound, the desired coating deposition rate, and desired thickness of the coating. It is of course within the invention to make layered coatings of two or more organosilane/oxygen-containing compound reaction products. It is also considered within the invention to employ two or more organosilanes simultaneously to make a "mixed" coating. Indeed, it is possible that the organosilane may be employed in conjunction with a non-organosilane to form either layered or mixed coatings.

[0028] Silane and organosilanes are toxic materials, and, depending on the organosilane, pyrophoric. Special care in handling these materials is warranted, preferably well-ventilated hoods. Electronic grade silane (SiH4) is available commercially in cylinders from Air Liquide America Corporation, Houston, Texas.
Trimethylsilane is available commercially from Dow Coming Corporation.

[0029] Preferred silicon-containing compounds include silane, and methyl-containing organosilanes; particularly those wherein the methyl-containing organosilane is selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane. Preferred organosilane compounds include methylsilane compounds having the structure SiHõ(CH3)4_,,, where n=1 to 3, i.e.
methylsilane, dimethylsilane, or trimethylsilane or the structure Si2H,,,(CH3)6_m, where m=l to 5. The most preferred organosilane compound is methylsilane, CH3SiH3.
The organosilane compounds are hydrolyzed by reaction with water, oxygen or water-containing gases such as humid air and/or other oxygen-containing gases, such that the carbon content of the deposited film is from 1 to 50% by atomic weight, preferably about 20%.
[0030] It is conceivable to employ adjuvants during the reaction of an organosilane with water. In the practice of the invention, "adjuvant" includes physical and chemical adjuvants, and combinations thereof. Suitable physical adjuvants include electrostatic discharge, plasma discharge, laser excitation, and the like, under temperatures and pressures suitable for each of these processes.
For example, plasmas are preferably best employed in moderate vacuum. A chemical adjuvant might include an oxidant gas such as oxygen, ozone, chlorine dioxide, combinations thereof, and the like. When a combination of physical and chemical adjuvants is employed, for example ozone and plasma discharge, the reaction product may be described as similar to the films produced by the process described in United States Pat. No. 6,054,379, issued April 25, 2000, teaching of the production of such films.

5 [0031] The container or surface to be treated maybe selected from the group consisting of iron, stainless steel (for example 301, 316, 401), aluminum, aluminum alloy, steel alloys and the like. The internal surface of the container, or the surface to be treated, may be subject to abrasion prior to reaction of the organosilane with water vapor in order to improve adhesion of the reaction product to the metal.
Residues 10 may be removed by a variety of mechanical means such as scrubbing, grinding, and peening. Scrubbing may be performed with non-woven abrasives. The use of lofty, fibrous, nonwoven abrasive products for scouring surfaces such as the soiled surfaces of pots and pans is well known. These products are typically lofty, nonwoven, open mats formed of staple fibers which are bonded together at points where they intersect and contact each other. The staple fibers of low-density abrasive products of this type can be, and typically are, bonded together at points of contact with a binder that may or may not contain abrasive particles. The staple fibers are typically crimped, have a length of about 3.8 cm, a diameter ranging from about 25 to about 250 micrometers, and are formed into lofty open webs by equipment such as "Rando-Webber" and "Rando-Feeder" equipment (marketed by the Curlator Corporation, of Rochester, N.Y. and described in U.S. Pat. Nos. 2,451,915; 2,700,188; 2,703,441 and 2,744,294).
One very successful commercial embodiment of such an abrasive product is that sold under the trade designation "Scotch-Brite" by Minnesota Mining and Manufacturing Company of St. Paul, Minn. ("3M"). Low-density abrasive products of this type can be prepared by the method disclosed by Hoover et al. in United States Pat. No.
2.958,593, issued on November 1, 1960.

[0032] Low-density, lofty abrasive products may also be formed of webs or mats of continuous filaments. For example, in United States Pat. No. 4,227,350 (Fitzer), issued on October 14, 1980, discloses a low-density abrasive product comprising a uniform cross-section, generally flat-surfaced, open, porous, lofty web of autogenously bonded, continuous, undulated, interengaged filaments. The web of Fitzer is formed by downwardly extruding a plurality of thermoplastic organic (e.g.
polyamide, polyester) filaments from a spinneret into a quench bath. As the filaments enter the quench bath, they begin to coil and undulate, thereby setting up a degree of resistance to the flow of the molten filaments, causing the molten filaments to oscillate just above the bath surface. The spacing of the extrusion openings from which the filaments are formed is such that, as the molten filaments coil and undulate at the bath surface, adjacent filaments touch one another. The coiling and undulating filaments are still sufficiently tacky as this occurs, and, where the filaments touch, most adhere to one another to cause autogenous bonding to produce a lofty, open, porous, handlable filament web. The web, so formed, is then impregnated with a tough binder resin which adherently bonds the filaments of the web together and also bonds a multitude of abrasive granules, uniformly dispersed throughout the web, to the surface of the filaments. Fibrous polishing and/or abrading materials can be prepared from continuous or substantially continuous synthetic filaments by the method disclosed by Zimmer et al., in United States Pat. No. 3,260,582, issued on July 12, 1966.
In this method crimped or curled continuous filaments are straightened out under tension into a substantially parallel relationship with one another, uniformly coated while under tension with an adhesive which may or may not contain abrasive particles, interlocked with one another by release of such tension and then set in a permanently interlocked and lofty, open, 3-dimensional state by curing or setting up the adhesive. Low-density, lofty, open, porous, nonwoven scouring articles have been more easily and economically manufactured from continuous filaments by the method disclosed by Heyer et al., in United States Pat. No. 4,991,362, and 5,025,596, issued on February 21, 1991 and June 25, 1991 respectively. The scouring pads described in these patents comprise a multiplicity of crimped or undulated, continuous, thermoplastic organic filaments that are bonded together (e.g., by fusion or an adhesive) at opposite ends.
The pad is made by arranging a multiplicity of continuous, crimped or undulated, thermoplastic organic filaments in an open lofty array, with one point of each filament in the array corresponding to a first filament bonding site and a second point of each filament, distant from the first point, corresponding to a second filament bonding site.
A pad is formed in the filament array by bonding substantially all of the thermoplastic organic filaments together at the first and second bonding sites. When a pad having greater abrasiveness is desired, abrasive particles may be adherently bonded to the filaments of the pad, preferably before the individual pad is cut from the filament array. These pads have also enjoyed commercial success and are economical to make.

United Sates Pat. No. 5,363,604, issued on November 15, 1994, decribes nonwoven scouring WO 03/008664 PCTlIB02/02770 articles comprising a low-density, lofty, open, porous, nonwoven web, the web comprising a multiplicity of crimped or undulated, continuous, preformed thermoplastic organic filaments, at least partially coated with an organic thermoset binder which binds the filaments at least at a portion of points where they contact. The continuous thermoplastic organic filaments, preferably in the form of tow, are entangled together at a multiplicity of points along their length to provide a cross-direction tensile strength the web of at least about 0.02 kg/cm, more preferably at least about 0.03 kg/cm, before coating the web with a thermosetting binder precursor solution. The continuous filaments are "entangled", preferably by needlepunching from a plurality of directions perpendicular to the machine direction.
Other background references include United States Pat. Nos. 3,688,453 issued on September 5, 1972; 4,622,253 issued on November 11, 1986; 4,669,163 issued on June 2, 1987;
4,902,561 issued on February 20, 1990; 4,927,432 issued on May 22, 1990;
4,931,358 issued on June 5, 1990; and 4,935,295 issued on June 19, 1990; World Patent Application No.
WO 92/01536, published Feb. 6, 1992; European Patent Application number 0 492 868 Al.
published Jul. 1, 1992.
(00331 Other means of removing residues from metal surfaces include grinding, such as by using so-called bonded abrasives. Bonded abrasives typically consist of a shaped mass of abrasive grains held together by a binder. The shaped mass can be in any number of conventional forms such as wheels, points, discs, and cylinders, but is preferably in the form of a grinding wheel. A preferred bonded abrasive product useful in the present invention comprises between about 50 to about 90 weight percent abrasive grains dispersed and adhered within a binder.
Bonded abrasives products are preferably manufactured by a molding process, and are made with varying degrees of porosity to control the breakdown. Bonded abrasives which with varying degrees of porosity to control the breakdown. Bonded abrasives which may be used for this purpose are such as those described in United States Pat. Nos. 5,250,085 issued on October 5, 1993:
5,269,821 issued on December 14, 1993; and 5,273,558 issued on December 28, 1993. Abrasive products dispersed throughout and bonded therein are well known and widely used.
Typically, the polymeric matrix is composed of either a hard, thermoset resin, such as a catalyzed phenol-formaldehyde, or resilient elastomer, such as a polyurethane or a vulcanized rubber.

[00341 Bonded abrasives are to be distinguished from coated abrasives in their construction and mode of operation. Bonded abrasives (e.g., grinding wheels) are three-dimensional structures of binder and abrasive grains which rely upon the continual breakdown and removal of the abrasive grains on the cutting surface to continually present sharp cutting points to the material being ground. Coated abrasives, on the other hand, typically have only a single layer of abrasive grains. See, for example, United States Pat. No. 5,011,512 issued on April 30, 1991.

[00351 When elastomeric binder matrices are used in bonded abrasives they generally produce an abrasive article having some degree of flexibility and resiliency.
These abrasive articles typically provide a smoother abrasive action and a finer surface finish than that provided by a bonded abrasive article made with hard, thermoset resin. As a result of this, elastomeric bonded abrasive articles have found a wide range of industrial applications, such as deburring, finishing, and sanding in the metal and wood-working industries. However, often these elastomeric bonded abrasive articles have shown premature loss of abrasive particles and, in some cases, undesirable smearing or transfer of portions of the elastomeric binder to the surface of the workpiece.

[00361 Conventional flexible bonded abrasive articles typically employ an elastomeric polyurethane as the binder matrix. The polyurethane binder matrix may be a foam, as disclosed in United States Pat. Nos. 4,613,345 issued on September 23, 1986, 4,459,779 issued on July 17, 1984, 2,972,527 issued on February 21, 1961, 3,850,589 issued on November 26, 1974; UK Patent Specification No. 1,245,373 (published Sep. 8, 1971); or the polyurethane binder may be a solid, as disclosed in United States Pat. Nos. 3,982,359 issued on September 28, 1976, 4,049,396 issued on September 20, 1977, 4,221,572 issued on September 9, 1980, and 4,933,373 issued on June 20, 1990.
[00371 For very large containers, such as ton units, bullets, and spheres, peening may be used with success to remove residues, scales and other deposits on internal surfaces of these containers. United States Pat. Nos. 3,638,464 issued on February 1, 1972 and 3,834,200 issued on September 10, 1974, disclose a high-intensity peening flap construction which includes an elongate strap of a flexible, tear-resistant material, and at least one metal peening particle support base fastened to the elongate strap. A
plurality of refractory-hard, impact fracture-resistant peening particles are metallurgically joined to an exposed face of the support base. In use, one or more of the flaps are mounted WO 03/008664 PCT/[B02/02770 on a hub, and the hub is rotated while the flaps are forced against the workpiece to be peened. The peening particles on each support base strike the workpiece in turn, thereby causing the peening particles to perform their normal peening function, but preventing the normal uncontrolled scattering which occurs in conventional shot peening. Improvements to these articles are described in United States Pat.
Nos. 5,179,852 issued on January 19, 1993 and 5,203,189 issued on April 20, 1993, to understand their use in removing residues.

[0038] Once the metal container inner surface, or metal surface to be treated is cleaned, and the reaction of organosilane with oxygen-containing compounds completed, either with or with out adjuvants, to form a coating, the processes of the invention comprise evacuating the container for a time and vacuum sufficient to remove substantially all erganosilane that has not reacted with oxygen-containing compounds. This first evacuation step preferably includes evacuation down to a vacuum of about 1_torr, more preferably down to 0.01 ton. The temperature during this evacuation process is not critical, but higher temperatures may tend to increase the removal rate of organosilane. This will be balanced by safety issues, in that higher temperatures may be more hazardous. Therefore, room temperature (about C), or slightly lower or slightly higher than room temperature is preferred.
[0039] Subsequent to this first evacuation step, the next step is exposing the coating to a gas composition, the gas composition having a concentration of reactive gas that is greater than an intended reactive gas concentration of a manufactured product. The reactive gas is caused to contact the coating and deactivate the surface even further. The reactive gas preferably has a concentration of at least 10 times the concentration of the reactive gas that is to be ultimately stored in the container or exposed to the surface, and more preferably has a concentration 500 times greater than the ultimate concentration, even more preferably 50,000 times the concentration of the reactive gas to be stored in the container or exposed to the surface.

[0040] The degree of adsorption of the reactive gas onto the coating depends in a complicated way on the composition and physical properties of the coating, the temperature and pressure employed during this step, as well as on the chemical and physical properties of the particular reactive gas that is being adsorbed thereon. These parameters are in turn dictated by the final concentration of reactive gas that is to be stored in the container. A discussion of adsorption of gaseous species onto surfaces that is helpful in this respect is included in Daniels, F. et al., "Experimental Physical Chemistry", Seventh Edition, McGraw-Hill, pages 369-374 (1970). While the 5 inventors are not certain, it is believed that the attraction of the reactive gas to the coating is physical in nature, involving an interaction of dipoles or induced dipoles, but may be chemical in nature involving chemical bonds, as when oxygen is adsorbed on charcoal. A combination of physical and chemical forces may be at work as well.
Thus, the surface area of a coating produced by the practice of the present invention 10 may be determined by the B.E.T. method, and preferably is at least about 1 m1/gram, more preferably at least 10 m2/gram. If the coating is somewhat porous, the pore volume may be determined by nitrogen adsorption isotherm methods, and is preferably at least 0.1 ml/gram. The B.E.T. method is described in detail in Brunauer, S. Emmet, P. H., and Teller, E., J.Am.Chem.Soc., 60, 309-16 (1938). The nitrogen 15 adsorption isotherm method is described in detail in Barrett, E. P., Joyner, L. G. and Helenda, P. P., J.Am.Chem.Soc., 73, 373-80 (1951) In general, if the concentration of reactive gas to be stored in the container is 100 ppb, then for the same reactive gas, same temperature and pressure, and same coating, the concentration of reactive gas used in this step will be higher than if the ultimate concentration of reactive gas is to be only 50 ppb, assuming adsorption is the governing pathway. An increase in temperature will tend to require an increase in concentration of reactive gas, an increase in pressure, or both, to achieve the same degree of adsorption. In contrast, a decrease in temperature will tend to require a decreased concentration of reactive gas, a decrease in pressure, or both to achieve the same level of adsorption.

100411 After the surface has been further deactivated by exposure to the reactive gas at high concentration, a second evacuation step is carried out to remove excess reactive gas. In this step, evacuation of the container is carried out for a time sufficient to remove substantially all of non-adsorbed reactive gas, leaving reactive gas adsorbed on the coating. The container is then filled with a gas composition comprising the intended low concentration of reactive gas.

[0042] Referring now to FIG. 1, there is illustrated schematically a logic diagram for carrying out processes of the invention. A container having a metal internal surface is selected at 12. The metal surface is exposed to a silicon-containing passivation material, 14, for a time and at a temperature and pressure sufficient to react most of the silicon-containing material with oxygen-containing compounds present on the metal surface. The container is then evacuated for a time sufficient to remove the bulk of the non-reacted silicon-containing material, at 16. Next, the metal surface is exposed to high concentration of reactive gas or liquid of the desired end product to be contained in the container, at 18. The container is again evacuated at 20 for a time sufficient to remove substantially all of the non-adsorbed reactive gas, then the container is filled with the composition having the desired material at the desired concentration, at 22. At this point, the container is allowed to equilibrate and the concentration of the gas in the container is tested at various times to determine the concentration of reactive gas in the container. If the shelf life is acceptable at 24, the product is made in accordance with the procedure followed, at 26. If the concentration of the gas increases or decreases beyondthe accepted tolerances, then the process of steps 20, 22, and 24 are repeated. Optionally, steps 14 and 16 may be repeated, as indicated at 26.
1. Examples [0043] In the following examples, hydrogen sulfide concentrations were measured using a chemiluminescence detector.

[0044] Comparative Example 1. Vacuum baking has long been employed to reduce moisture in cylinders to prevent and/or decrease corrosion due to acid as reactions with moisture and the cylinder wall (and cylinder valve). However, as illustrated in FIG. 2, vacuum baking an aluminum cylinder at 65 C to vacuum of 1 micrometer of Hg for 3 days was not sufficient to provide stability of a 150 ppb H2S balance nitrogen mixture for a cylinder which was previously exposed to moisture.
[0045] Comparative Example 2. Passivation of the cylinder and valve after vacuum baking with a high concentration of the gas mixture to be prepared has also been used to extend shelf life of high purity mixtures. However, this has not proved successful. After an initial vacuum baking as in Comparative Example 1, the cylinder was subsequently filled with 5000 ppm of H2S balance nitrogen and heated at 80 C
for 3 days. After 3 days the contents were emptied and a vacuum pulled on the cylinder in order to remove all residual H2S. The cylinder was subsequently filled with 150 ppb H2S balance nitrogen. As illustrated in FIG. 3, although the stability of the mixture was enhanced, a fast decay was still observed.

[0046] Example 1. Silane, a silicon-containing material having the formula SiH4, is known to react with moisture and other oxygen-containing compounds and hydrogen. It has also been reported that Si02 can bind to aluminum, and we have data indicating formation of weak Si-Al bonds when treating an aluminum alloy cylinder known under the trade designation "Calgaz 3003". In this example, a 1 percent silane balance nitrogen mixture was introduced into an aluminum cylinder (note: this was not a cylinder known under the trade designation "Calgaz 3003") and left in the cylinder overnight. Subsequently the balance was vacuumed out and the cylinder was filled with a 250 ppb H2S balance nitrogen mixture. As illustrated in FIG. 4, the signal decay for the curve labeled "No H2S Passiv" was slower than observed previously, indicating that the reaction of moisture with the H2S was not solely responsible for the loss of stability of the H2S. The cylinder was subsequently evacuated and passivated with a 5000 ppm mixture of H2S at 62 C. The cylinder was evacuated and filled with 150 ppb H2S. The signal was observed to increase with time, indicating that substantially all of the passivation mixture had not been removed prior to filling.

[0047] Example 2. Applying the same silane treatment followed by H2S
passivation as in Example 1, but using a longer vacuum. time period to remove extraneous silane, it was possible to achieve a stable H2S mixture, as illustrated in FIG. 5 by the curve labelled "H2S Passivated."

[0048] Although the description herein is intended to be representative of the invention, it is not intended to limit the scope of the appended claims.

Claims

What is claimed is:

1. A manufactured product comprising a gas having an extended shelf-life, the product comprising:
a) a container having an internal space and a clean and passivated internal metal surface;

b) a composition comprising a reactive gas that is 1) contained within the internal space and in contact with the clean passivated internal metal surface, the reactive gas having a concentration that is substantially maintained at a concentration of 1000 ppb or less within a matrix gas; and 2) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, acid gases which are inert in relation to silicon-containing materials, and mixtures thereof;
and c) wherein the clean and passivated internal metal surface comprises:
1) the reaction product of a silicon-containing material selected from the group consisting of compounds within the general formula:
SiR1R2R3R4 wherein R1, R2, R3, R4 are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl and an oxygen-containing material selected from the group consisting of H2O, N2O, CO2, molecular oxygen, metal oxides, and mixtures thereof., and 2) an effective amount of the reactive gas adsorbed on the reaction product by exposing the reaction product on the internal metal surface to the reactive gas having a concentration at least 10 times the concentration of the reactive gas being substantially maintained in step b), the amount of reactive gas having a concentration adsorbed thereon resulting from the previous exposure of the reaction product to the reactive gas before the evacuation of the reactive gas from the internal space and prior to filling the internal space with the composition.

2. The product of claim 1 wherein the clean and passivated internal metal surface comprises:
a) a coating comprising SiO2, and b) an effective amount of the reactive gas adsorbed on the coating by exposing the internal metal surface to the reactive gas having a concentration at least times the concentration of the reactive gas being substantially maintained in step b), the amount of reactive gas having a concentration adsorbed thereon resulting from the previous exposure of the reaction product to the reactive gas before the evacuation of the reactive gas from the internal space and prior to filling the internal space with the composition.

3. The product of claims 1 or 2, wherein said internal metal surface is aluminum or an aluminum alloy, wherein the reactive gas comprises an acid gas and said acid gas is selected from the group consisting of carbondisulfide, carbonylsulfide, and compounds within formula (I):

Y-S-X (I) wherein S is sulfur, and X and Y are the same or different and are independently selected from the group consisting of hydrogen, alkyl, aryl, oxygen, hydroxyl, amino and aminosilane; wherein the concentration at which the reactive gas is being substantially maintained is 500 ppb or less; and wherein the concentration of the exposed reactive gas is at least 50,000 times the concentration of the reactive gas being substantially maintained in step b).

4. The product of claim 1 wherein said metal is selected from the group consisting of aluminum, aluminum alloys, steel, iron and combinations thereof.

5. The product of claim 1 wherein said silicon containing material is a methyl-containing silane.

6. The product of claim 5 wherein said methyl-containing silane is selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane.

7. The product of claim 1 wherein the composition has a reactive gas concentration of about 500 ppb and does not vary by more than +/-15 percent.

8. The product of claim 1 wherein the composition has a reactive gas concentration of about 100 ppb and does not vary by more than +/- 20 percent.

9. The product of claim 1 wherein the composition comprises a single reactive gas mixed with a matrix gas selected from the group consisting of an inert gas, a hydrocarbon gas, and mixtures thereof.

10. A method of making the manufactured product of claim 1 from a clean container, the method comprising the steps of:
i) exposing an internal metal surface of a container to a first fluid composition comprising a silicon-containing compound for a time sufficient to allow at least some of the silicon-containing compound to react with an oxygen-containing compound present to form a silicon-treated surface on at least some of the internal metal surface, the silicon-containing compound selected from the group consisting of compounds within the general formula:
SiR1R2R3R4 wherein R1, R2, R3, and R4 are the same or different and are independently selected from the group consisting of hydrogen, halogen, alkyl, aryl, amine, halogenated alkyl, and halogenated aryl and the oxygen-containing compound selected from the group consisting of H2O, N2O, CO2, molecular oxygen, metal oxides, and mixtures thereof;
ii) evacuating the container for a time sufficient to remove substantially all silicon-containing compound that has not reacted with the oxygen-containing compound to form the silicon-treated surface;
iii) exposing the silicon-treated surface to a second fluid composition, the second fluid composition comprising a reactive gas:
a) having a concentration within a matrix gas that is at least 10 times the intended reactive gas concentration of the manufactured product; and b) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, acid gases which are inert in relation to silicon-containing materials, and mixtures thereof;
and iv) evacuating the container for a time sufficient to remove substantially all of-the second fluid composition, thus forming said passivated internal metal surface in the container; and v) filling the container with a third fluid composition having the intended reactive gas concentration for the manufactured product.

11. The method of claim 10 wherein the silicon-containing compound is selected from the group consisting of silane and a methyl-containing silane.

12. The method of claim 11 wherein said methyl-containing silane is selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane and tetramethylsilane.

13. The method of claim 10 wherein steps i) and ii) are repeated prior to step iii).

14. The method of claim 10 wherein the concentration of the silicon-containing compound used in step i) ranges from 100 ppm to 100 percent.

15. The method of claim 10 wherein during step i) the first fluid composition is heated to a temperature of not more than 74°C.

16. The method of claim 10 wherein during step iii) the second fluid composition is heated to a temperature of not more than 74°C.

17. A method of making a device having a passivated metal surface, the method comprising the steps of:
i) exposing a metal surface to a silicon-containing compound selected from the group consisting of compounds within the general formula:

SiR1R2R3R4 wherein R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, halogen, amine, alkyl, aryl, halogenated alkyl, and halogenated aryl, for a time sufficient to form a silicon treated surface on at least some of the metal surface;

ii) evacuating the metal surface for a time sufficient to remove silicon-containing material that has not reacted with oxygen-containing compounds on the metal surface to form the silicon-treated surface, the oxygen-containing compounds selected from the group consisting of H2O, N2O, CO2, molecular oxygen, metal oxides, and mixtures thereof;

iii) exposing the silicon-treated surface to a gas composition, the gas composition comprising a reactive gas::

a) having a concentration within a matrix gas that is at least 10 times the intended reactive gas concentration of gas to be contained in the device;
and b) selected from the group consisting of nitrous oxide, nitric oxide, hydrogen chloride, chlorine, boron trichloride, acid gases which are inert in relation to silicon-containing materials, and mixtures thereof; and iv) evacuating the silicon-treated surface for a time sufficient to remove substantially all of said gas composition and thus forming a passivated metal surface.