Full opinion text
MEMORANDUM OPINION KEADY, District Judge. In these consolidated cases, the Dow Chemical Company sues Halliburton Company and Mississippi Power & Light Company for patent infringement. Both defendants deny infringement, asserting that the patents in suit are invalid and unenforceable and they seek a declaratory judgment of noninfringement, invalidity, and unenforceability as to each patent, together with an award of attorney’s fees. After lengthy discovery and submission of a pretrial order, the court severed the issues of liability and reserved the question of damages. Following an evidentiary hearing, the court referred the transcript of testimony and exhibits to the United States Magistrate for preliminary review and recommendations. Upon receipt of the Report and Recommendations, both sides filed written objections. Upon careful review of the evidence and the objections taken to the magistrate’s report, the court makes findings of fact and conclusions of law required by Fed.R.Civ.P. 52(a) as follows. FINDINGS OF FACT I. THE PARTIES Plaintiff, The Dow Chemical Company (Dow), is a Delaware corporation having its principal office and place of business in Midland, Michigan. Defendant, Halliburton Company (Halliburton), is a Delaware corporation, duly authorized to do business in Mississippi and having a place of business at Amory, Monroe County, Mississippi. Defendant, Mississippi Power & Light Company (MP & L), is a Mississippi corporation, duly authorized to do business in Mississippi and having a place of business at Greenville, Washington County, Mississippi, within the Northern District of Mississippi. Both Dow and Halliburton are regularly engaged in the business of industrial cleaning, among other things. Mississippi Power & Light Company is an electric power utility corporation regularly engaged in the business of generation, transmission, and distribution of electric power. II. THE PATENTS AT ISSUE Dow is the owner of each of the patents in suit, i.e., the Lesinski patent, U.S. Patent 3,308,065 (Lesinski ’065 patent), and U.S. Reissue Patent 30,796, the Teumac patent, U.S. Patent 3,413,160 (Teumac ’160 patent), and the Harriman et al patent, U.S. Patent 3,438,811 and U.S. Reissue Patent 30,714 (Harriman ’811 patent). The Lesinski patent was issued to Dow on March 7, 1967. It was returned to the Patent and Trademark Office and replaced by Reissue Patent 30,796 on November 7, 1981. The application for reissue was filed September 14, 1978. The Harriman patent was issued to Dow on April 15, 1969. It was returned to the Patent and Trademark Office and replaced by Reissue Patent 30,714 on August 18, 1981. The application for reissue was filed September 14, 1978. The Teumac patent was issued to Dow on November 26, 1968. III. CLAIMS In GC 78-31-K-P, Dow charges infringement by Halliburton of claim 6 of the original and reissue Lesinski patent, infringement of claim 6 of the Harriman patent, now claim 10 of the Harriman reissue, and infringement of claims 4 and 10 of the Teumac patent, and further alleges that infringement by Halliburton has been willful and deliberate. In GC 78-32-K-P, Dow charges MP & L with infringement of the above-stated claims of two of these patents, i.e., Lesinski and Harriman. IV. UTILITY BOILER TUBE SCALE BUILDUP AND REMOVAL, AND THE PROCESSES IN ISSUE AND THEIR GENERAL BACKGROUND A. Steam Boiler Construction, and Tube Scale Formation and Its Effect on Power Generation A utility power station’s steam generating equipment makes steam in large boilers at high pressure to continuously drive turbines which generate electricity. Water circulates through hundreds of vertically extending small diameter steel tubes which form the shell of a large fire box, typically 40 to 50 feet wide and up to 90 feet deep. The tubes rise vertically up to 200 feet to a steam drum 3 to 5 feet in diameter and up to 90 feet long. With continuous use, the tubes develop internal wall scale, which is mostly iron oxide consisting of magnetite, Fe.304, and hematite, Fe203, but which may contain some copper and water hardness deposits, such as calcium or magnesium compounds. These scales undesirably insulate the fire box heat from water inside the tubes. When the scale becomes sufficiently thick, tubes overheat, and will ultimately rupture, due to localized scale buildup and high internal pressure, typically 2,700 lbs. per square inch. A single tube rupture will cause shutdown of the entire boiler for time-consuming mechanical repair. The loss to a utility from boiler shutdown is about $60,000 per day per 100 megawatts of generating capacity. With typical commercial utility boilers of 300 to 1,300 megawatt capacity, the loss can range from $200,000 to $800,000 per day. B. Scale Removal Methods Prior to the Process In Issue Utility companies for many years have employed preventive maintenance to remove boiler scale buildup. Prior to World War II, cleaning was done mechanically by drilling scale out of the tubes. This procedure required such a long downtime that chemical cleaning was developed as a replacement. Dow introduced the first utility boiler tube chemical cleaning method in 1939. This process employed a hydrochloric acid (HCL) solution to dissolve iron oxide scale. For boilers having copper content in the scale, Dow developed and used an ammonium brómate solution to dissolve copper in a second step separate from the iron oxide-dissolving step. These processes were used in the utility industry in this country from the early 1940’s through the mid-1950's. In the 1950’s, citric acid was used for cleaning “once-through” boilers with light oxide scale deposits, and at the same time sodium nitrite was introduced for passivating iron surfaces, or rendering the surfaces rust resistant. Problems developed with citric acid precipitates in boilers containing heavy iron oxide scale deposits, and in the late 1950’s, cleaning mixtures of citric acid and formic acid were used. In 1961, Dow offered a mixed formic acid-hydroxyacetic acid solution, called the L23 Process. In the late 1950’s, Dow modified its HCL process by adding a copper complexer to enable removal of iron oxide and copper with a single solution. This process became the volume workhorse of the utility boiler chemical cleaning industry. Cleaning solutions consisting of sodium etheylenediamine tetraacetic acid (EDTA) and added chemical reducing agents also were used during this time. In 1961, Pfizer Corporation introduced a citric acid (CA) solution for dissolving both iron oxide and copper which employed an acid solution of ammoniated citric acid to dissolve iron oxide scale, and a sequential step using an alkaline ammoniated citric acid solution for copper removal; this was called the Citrosolv Process. This process employed an ammoniated chelate as a means of minimizing precipitation of iron compounds or alkaline pH. C. Dow’s Vertan 675 ACR Process Using the teachings of the Lesinski patent, Dow developed the first aqueous alkaline solution of a single active constituent, ammonium EDTA, to dissolve iron oxide scale from a metal surface, and introduced that process to the utility industry in the United States in late 1961. Dow designated the process “Vertan 675 Process.” In 1964, Dow modified its Vertan 675 Process to incorporate the teachings of the Harriman patent to enable removal of copper immediately following the completion of the iron oxide removal stage by oxidizing the single fill of the alkaline ammonium EDTA solution to dissolve copper. Dow designated this process the “Vertan 675 Alkaline Copper Removal (ACR) Process.” Dow’s Vertan 675 Process for dissolving iron oxide scale in broad terms, consists of preparing an ammoniated EDTA concentrate of about 38%-39% EDTA at a pH between about 8 to 11, usually about 9, injecting that concentrate into the boiler to be cleaned to form a dilute water solution, raising the temperature of the solution to between 250° to 350° F., and circulating the solution through the boiler for a time sufficient to dissolve the iron oxide scale in the boiler. During the cleaning operation, the concentration of the iron EDTA chelate formed by the dissolving solution and the free EDTA is continuously monitored, and an excess of free EDTA is maintained to assure complete dissolution of the iron oxide. Iron oxide removal is deemed complete when successive chemical analyses show no further EDTA chelate formation. As originally practiced, after dissolving the iron oxide the boiler was drained and rinsed, and a passivated, or rust resistant, surface was obtained. During late 1962 and 1963, Dow’s Industrial Service Division successfully removed iron oxide scales from utility boilers in the United States using Vertan 675, and employed these early jobs to develop acceptable commercial embodiments of the ’065 Lesinski process. In 1963, Dow’s Nesbitt conducted the first Vertan 675 boiler cleaning job outside the United States on a Sulzer boiler in Holland to remove iron oxide only; this job was successfully completed. In the Holland job, Nesbitt was assisted by Preston Engle, who was then a Dow employee in the Technical Department in Tulsa. After returning to Dow in the summer of 1963, Engle left Dow and was hired by Halliburton in the early fall of 1963. In Dow’s Vertan 675 ACR Process, the iron oxide removal steps are the same as in the Vertan 675 Process. In order to remove copper, the temperature of the ammoniated EDTA solution containing both the ferrous EDTA chelate and free EDTA is lowered to the range of about 180°, instead of draining the solution, and air is sparged into the boiler. While air blow continues, copper analyses and oxidation potential measurements of repetitive samples of the solution are made to determine when all of the copper has been dissolved. The air blow is discontinued when both types of measurements indicate copper removal is complete. D. Vertan 675 ACR Process Compared to Other Chemical Cleaning Processes Dow’s 675 ACR Process removes both iron oxide and copper with one unit fill of the alkaline ammonium EDTA solution. This feature saves several unit volumes of water, saves chemicals and saves time over conventional acid cleaning methods such as HCL and CA. In the Citrosolv process, iron oxide is removed at an acid pH of 3.5; the solution is then adjusted, on the job, to an alkaline pH of about 10 for copper removal. The Vertan 675 solution allows firing of the boiler to control temperature, whereas HCL solutions must be heated to a narrow usable temperature outside the boiler before injection; this results in an important saving in downtime when using Vertan 675 instead of HCL. The alkaline Vertan 675 solution is less corrosive, and safer and easier to handle than HCL solutions. After a cleaning job is completed, Vertan 675 solution is easily disposed of by burning, whereas HCL solutions require expensive preparation prior to disposal to avoid pollution. Even though Vertan 675 chemicals cost more than HCL and Citrosolv chemicals, overall savings result from less downtime, no need for extra piping for handling and pumping heated acid solution, and fewer required specialized technicians. After commercial introduction in 1963, Dow’s Vertan 675 Process for removing iron oxide received slow acceptance by the domestic utility industry in competition with the acid cleaning solutions then available. After 1964, when Dow added the alkaline copper removal process of the Harriman patent to enable the sequential removal of iron oxide and copper with a single unit fill of solvent, trade acceptance began to grow. By 1979, the Vertan 675 ACR Process had become the major process in use in the cleaning of utility boilers in the United States. E. Acquiescence by Halliburton in Validity of the Claims in Issue From 1969 to 1977 Preston Engle co-authored a paper with Lesinski and Blake in October 1962 which described the Lesinski invention in general terms. The paper did not identify the ammoniated aqueous pH 9 solution; all that it mentioned was alkaline EDTA chelants, and that iron oxide could be dissolved from boilers in a closed system at pH 9 with “a formulated solution of EDTA (Vertan 675).” Engle learned about the Lesinski discovery in 1961 from Lesinski, and performed additional development work for Dow in the process; he provided the data set forth in the ’065 patent as Examples 4, 5 and 6. Engle had knowledge of the first actual boiler cleaning job using the ’065 process in Dow’s Midland boiler in July and August 1961, and thereafter was involved in development of the Vertan 675 process. He represented the process to Dow customers as a “breakthrough in the science of chemical cleaning,” and so regarded it himself. Until about the spring of 1963, Engle actively conducted or directed Dow research on the use of inhibitors for the Vertan 675 process and on the problem of copper deposits. Additionally, Engle also prepared releases to the trade on the use of ammoniated EDTA. In the fall of 1963, after obtaining field experience in the United States and in Holland in boiler cleaning with Vertan 675, Engle left Dow and joined Halliburton. At Halliburton, Engle became Technical Advisor of Halliburton’s Industrial Cleaning Services, and in that position initiated Halliburton’s interest in Vertan 675. Prior to that time, Halliburton had done no work with ammoniated EDTA. By the fall of 1964, Engle called on Dow Vertan 675 customers on behalf of Halliburton, and in July 1965 complained to Kellogg Company about specification of Vertan 675 in their cleaning jobs. The first ammoniated EDTA job which Halliburton conducted was cleaning No. 5 boiler at Kaiser Aluminum’s Baton Rouge Plant on August 22 and 23, 1966, approximately seven months before the ’065 patent issued. Engle was the technical advisor on that job. After successful completion of the b,oiler cleaning, Engle wrote the final repórt setting forth the details of how that job! was performed. After completion of the Kaiser job, Halliburton received a request from M.W. Kellogg Co. for a bid on a boiler cleaning job which specified use of ammonium EDTA. After review of the specifications for the Kellogg job, which referred to Vertan 675, Engle forwarded them in September 1966 to Paul Leonard of the Halliburton Patent Department, and requested Leonard to determine if Dow had a patent on the described material and process. Halliburton’s attorney Leonard advised that it was unlikely that a patent could issue to Dow on the broad idea of cleaning metal with an ammoniated EDTA process. Halliburton’s Washington attorney Grove, however, cautioned that a patent on ammonium EDTA for cleaning metal surfaces could possibly be obtained “if it was a fact that ammonium EDTA performed in an unexpectedly superior manner to the sodium salts of EDTA.” At trial, Engle admitted that ammonium EDTA by itself is unexpectedly superior to sodium EDTA by itself for dissolving iron oxide. On October 10, 1966, Leonard advised Engle that it was safe to proceed with Halliburton’s plan to use ammoniated EDTA solvent to clean boilers because Dow had no patent on the “Kellogg” process, and “should a patent issue, we can then study its validity.” Engle taught Halliburton personnel how to use ammoniated EDTA, how to mix components to make EDTA, how to maintain a slight excess to produce passivation, and advised Halliburton personnel that they should operate “that cleaning solution at a pH of about 9.9 to 9.5.” After Dow’s ’065 patent issued in March 1967, Ledlie of Dow’s Patent Department called Halliburton’s attention to the issuance of the patent in a letter dated April 3, 1967, receipt of which was acknowledged by Halliburton on April 5, 1967. Engle was advised of issuance of the Lesinski patent and the April 3, 1967, letter from Dow. On May 3, 1967, he advised his superior, Harris, that: The references cited by the Patent Office against the subject patent have been reviewed. I have also reviewed my personal records. I could not find anything which could be used to defend our right to continue use by this compound. In view of the notice issued us by Dow, it is my opinion that we should not further endanger our position by continuing to use the material. If you concur in this opinion, and if it is the expressed desire of management, I will advise our field people accordingly. On November 30, 1967, Halliburton further responded to Dow’s notice of April 3, 1967, stating that Halliburton considered the Lesinski patent invalid in view of a Bersworth Patent 3,033,214. By March 1969, Engle had heard of Dow using air in its Vertan process to remove copper, and inquired from Halliburton’s Patent Department if the use of air would avoid infringement of the ’065 patent. He was advised that it would not. On December 1, 1969, Dow’s patent attorney Lilly called Halliburton’s patent attorney Tregoning and discussed Halliburton’s position as to validity of the Lesinski patent, and infringement of the patent by Halliburton. Halliburton’s Tregoning promptly met with Harris, Engle, and Hathorn, Vice-President of Research and Development, to consider overcoming Dow’s charge of infringement of the ’065 patent by obtaining a license under the patent. Before the meeting, Tregoning had given consideration to the questions of validity and infringement and had seen the invalidity opinion prepared in June 1967. After the meeting, Halliburton decided to discuss a license proposal with Dow. Tregoning contacted Lilly and proposed a meeting to be held in Tulsa on December 18, 1969, to discuss the question of licensing. The meeting was agreed upon, but Tregoning cancelled the meeting upon learning that Dow was unwilling to license; he advised Lilly that: Our position was simply that if there had been any infringement in the pst, this was a thing of the past, and that we would now look to the present undertaking and determine whether or not infringement did exist. Our purpose was to avoid infringement. Lilly was satisfied with this arrangement, and was perfectly willing to forget the past since it involved very little. Between December 10 and December 23, 1969, Engle notified Halliburton Industrial Service Division managers by telephone that they were not to use ammonium EDTA. During 1970, Halliburton field salesmen maintained the desire to bid on ammoniated EDTA cleaning jobs, but Halliburton management remained firm that Halliburton was not to use the process. On July 24, 1970, Halliburton’s Dillman advised Engle that: We are being asked constantly if we can used Ammoniated EDTA for Fe. We are also being asked if we can use Ammoniated EDTA for iron and copper removal (ACR) and if we can’t, what are we recommending in its place! I believe the situation is serious and will continue to become more so. [L]et me summarize some of the needs for research if we are going to survive especially in the field of electric utilities: 3. We need permission to use or possibly use without permission, the Ammoniated EDTA until we are absolutely prohibited from using it by a Court order____ 4. We need, in addition to the above use of Ammoniated EDTA, to get clearance to adapt it to the removal of copper (such as ACR) or a similar variation of the same. If the ACR method cannot be used, then we need to pursue a method equal or better. Dillman’s opinion was that the best process Halliburton had to offer was the HCL process combined with ammoniated citric for neutralizing and removing copper, and that the Citrosolv process was not an acceptable alternative to ammoniated EDTA. Laboratory Technical Manager Harris responded to Halliburton’s Indiana salesmen in August 1970: As you know a patent exists on the use of this solvent. After we were unsuccessful in negotiating a license using this method, it was decided that other procedures for cleaning would have to be substituted____ We did inform all industrial cleaning personnel of the difficulty we might be faced with in the event we ran ammoniated EDTA. However, they were also told not to use the process until further notice. This decision is still in effect. On August 11, 1971, Tregoning took the position that: Dow U.S. Patent 3,438,811 certainly provides information which, when added to the coverage Dow has via U.S. 3,308,065 and 3,413,160, does establish a position which we will respect until additional information is forthcoming, i.e., information such as would defeat their position. In June 1973, Engle assessed the market potential for ammoniated EDTA materials and advised Laboratory Technical Manager Harris: 1. Dow has a patent for the removal of iron oxide and copper. 2. Our only prior use was for the removal of mill scale and some operational deposits, none of which contain copper. 3. The market potential greatly depends on the capability to remove copper as well as iron oxide. Without the capability to remove copper, the market is severely restricted. 5. It is rather common knowledge in the industry that Dow has had problems during their promotion of their material. Engle further advised that the total estimated annual market for ammonium EDTA for pre-operational and operational boiler cleaning amounted to approximately $750,-000 for costs of chemicals only. This estimate assumed conversion of the entire market to ammonium EDTA cleaning, which was considered an unlikely prospect. Halliburton sales personnel gave quotations to customers for ammoniated EDTA jobs during 1975 and 1976. Some of these bids were awarded to Halliburton, but Halliburton management still adhered to its decision to refuse to permit actual performance of such jobs. Jobs at Detroit Edison, Northern Indiana Public Service, and Columbus and Southern Electric were successfully negotiated by Halliburton salesmen, but were not performed due to Halliburton’s management decision. In May 1976, Engle arranged a number of customer contacts in the Chicago district to discuss cleaning with ammoniated EDTA, but was stopped by Hathorn, Halliburton’s Vice-President of Research and Development. In September 1976, John Dillman, manager of Halliburton’s Pittsburgh Division, raised the question of reversing Halliburton’s management decision concerning ammoniated EDTA. In a letter, he stated: John Tregoning said Don Hathorn made the decision to stop pursuing MACOR. [Halliburton’s accused ammoniated EDTA process]. He also requested me to send him a memo pointing out the increasing popularity of Vertan 675 (ACR) (MACOR), the tremendous potential its usage represents, our cost and bidding price and any other comments deemed important____ Briefly, in the year we were allowed to pursue this, we were coming to the point of harvest____ Many ... requested our bid on MACOR which we gave them, along with our optional recommendation of Citrosolv. The mere fact that we could give them a choice, sold several Citrosolv jobs once they made the cost comparison. We no longer make this comparison. We still get many requests, but we decline bidding or discussing MACOR. As a company, and as individuals, we are embarrassed. In October 1976, John Gatewood reported to Laboratory Technical Manager Harris: Let me take this opportunity to bring you up to date on the Water Conference in Pittsburgh this week. In addition to the usual visiting at such a conference, this year there appeared to be two primary topics of interest and discussion with both Halliburton personnel and with customers. One of these topics is ammoniated EDTA. Both John Dillman and Glenn Morris feel very strongly that Halliburton should go ahead and offer to customers the MACOR process which we began to do about a year ago. Morris states quite firmly that we are losing three million dollars a year in the Dwight, Illinois district alone by not using the ammoniated EDTA for boiler cleaning. John Dillman feels that Halliburton management made the decision to not go with EDTA based on projected revenue figures which were unrealistically low. John Dillman completed a market survey on Vertan 675 and MACOR in the fall of 1976, and reported that: Based on a conservative survey of the usage of the reference subject by all IC locations in the Pittsburgh Division, it is estimated that $7,214,000 are spent per year for boiler cleaning____ Prior to our position of not being allowed to offer or quote on MACOR, we would use our MACOR quote to sell an optional cleaning method using Citrolsolv which can be incenerated [sic] just as the Vertan or MACOR can. Since this time, we have declined to bid on MACOR and our Citrosolv work has declined to very near stopping. As you are aware, we have started a more concentrated effort to get business in Western Pennsylvania. The big thing we have encountered is “Can you compete with D.I.S. on Vertan ACR,” “If you can you can bid on our jobs.” Dillman further reported that Pennsylvania Electric had an upcoming boiler cleaning job, and that, “[w]e will get an invitation to bid but must be able to bid on the Vertan 675 (MACOR) portion or nothing at all.” By December 1976, Vice-President Hat-horn of Halliburton was being repeatedly requested to reverse his decision concerning Halliburton’s use of ammoniated EDTA in the MACOR process. Mr. Hathorn was advised: Our inability to utilize MACOR continues to plague us.daily____ More and more of our customers are asking for competitive bids utilizing Ammoniated E.D.T.A. Many times a total system cleaning will be predicated on our ability to clean the boiler using ammoniated E.D.T.A. If we cannot do the boiler using this material, we lose the entire system---- As you can see, time is of the essence. Any effort you can make that will allow us to recoup this lost market, as well as take advantage of the expansion that will be caused by the July, 1977, E.P.A. Standards ... will be appreciated. In February 1977, Glenn Morris of Halliburton complained about the inability to use ammoniated EDTA and stated: We are having some problems getting hydrochloric acid as you know. It has become very expensive and will go higher. It is also causing a great amount of disposal problems for our customers. We have lost many thousands of dollars because of Vertan. Let's go with MACOR. On March 2, 1977, Dillman reported on numerous customers unwilling to accept Citrosolv or ammonium brómate, Halliburton processes in competition with Vertan 675, and stated: As stated many times, we need to be able to quote on MACOR for iron and copper removal, more especially after July, 1977, when E.P.A. regulations for discharge of waste water and chemicals goes [sic] into effect. After permission is granted, we still have a long road ahead. Finally, there is every indication from throughout this entire division that Vertan 675 (ACR) will be the chemical cleaning solution and method in the majority of cases____ Sometime between March 2 and March 21, 1977, Halliburton’s management reversed its position on Halliburton’s use of ammoniated EDTA processes. On March 21, 1977, Dillman announced that “[w]e are now free to bid and use MACOR for all phases of chemical cleaning. This includes operational cleaning for removal of Fe and Cu.” F. Halliburton’s Failure to Develop a Noninfringing Process With the Ammoniated Dequest Chelant In December 1969, following the aborted meeting with Dow to discuss the possibility of obtaining a license of the Vertan 675 Process, Halliburton’s technical personnel Engle, Frost, Smith and Knox met to formulate a research program to “look at other possible systems for simultaneous copper and magnetite removal” because of Dow's infringement notice to Halliburton of the Lesinski patent. Halliburton’s technical team wanted to develop a high pH alkaline process as a replacement for Dow’s ammonium EDTA system. They rejected HCL, CA and sodium EDTA, and turned to chelating materials commercially available from Monsanto Chemical Co. under the trademark “Dequest.” The Dequest materials were chelant chemicals advertised by Monsanto for use in complexing metal ions such as iron, copper, etc., and as having the same “or superior metal sequestering properties as EDTA.” The Dequest chelants are phosphoric acids as opposed to alkylenepolyamine tetraacetic acids. By March 19, 1970, a first report of the early results obtained from using such materials was made by Dr. Frost, who acknowledged that the Lesinski patent “is worded such that it covers all ammonium or amine salts of alkylenepolyamine polycarboxylic acids.” Dr. Frost received the assignment of the development of a high pH solvent from Francis Anderson, Halliburton Laboratory Manager. Frost’s belief was that in locating Dequest materials he had “a series of inexpensive and commercially available chemicals which offer an alternative to, and possibly an improvement over, EDTA and other alkylenepolyamine polycarboxylic acids.” By May 1970, Frost completed his initial evaluations in the laboratory, and concluded that the Dequest materials best dissolved magnetite, Fe304, at an acid pH of .4-6, but that Dequest 2010 was able to dissolve magnetite at a pH as high as 8.5 at relatively high temperatures. After considering the initial results with Dequest reported by Dr. Frost, Preston Engle advised Halliburton’s Lab Supervisor, Knox, in July 1970, that additional testing and a number of questions had to be answered before a field trial could be carried on with the Dequest process. In December 1970, Engle further advised that such studies should be done as quickly as possible. In August 1970, Halliburton offered a commercial cleaning process for dissolving iron oxide which does not infringe the claims of the Dow patents in suit. That process uses tetrasodium EDTA solvent in conjunction with dextrose as an added reducing agent for removing iron oxides from ferrous surfaces. This process employs an aqueous solution at a pH of 10.5 at a temperature not exceeding 200° F, because dextrose decomposes at temperatures above that level, and, without the added dextrose sugar, the ability to dissolve iron oxide is lost. Even with the added reducing agent, sodium EDTA is not competitive with ammonium EDTA for boiler cleaning. In October 1971, Dr. Frost reported that at temperatures of 180° — 300° F, the performance of Dequest 2010 was equal to ammoniated EDTA. In April 1972, Dr. Frost, as co-inventor with Knox and Martin, filed for patent on a method for removing magnetite scale from a metal surface using Dequest chelants at an alkaline pH. The patent issued in December 1974 with 14 claims. The process of claim 1 uses an aqueous Dequest solution at a pH of 9 to 10.25 and a temperature of about 180° to 300° F for a contact period of at least an hour to dissolve magnetite from a ferrous metal surface. By September 1972, after almost two and one-half years of research, Dr. Frost reported that the Dequest 2010 material at pH 9 to 9.5 was a satisfactory solvent for boiler scales and was ready for field trial. The impetus for trying Dequest in the field was the pressure of customers requesting that Halliburton supply a process competitive with Dow’s ammoniated EDTA Vertan 675 Process. Laboratory Technical Manager Harris was advised in October 1974: We desperately need a material competitive with ammoniated EDTA. Our largest customer (blank) insisted on bids on the use of this formulation for a recent job at the (blank). The job was to do a chemical clean on a boiler showing evidence of hydrogen damage. The recommendation to stay on the alkaline side all the way was made by (blank). We were advised by Duncan that we could not bid on ammoniated EDTA, due to competitive patents____ In November 1974, a commercial power plant boiler cleaning job was attempted by Halliburton using the high pH Dequest solvent, ammoniated HLX-157. The cleaning attempt produced “substantial amounts of undesired white precipitate,” which was considered to be a serious deficiency. Since the heavy precipitate experience using the Dequest compounds in November 1974, Halliburton has not used, or recommended the use of, Dequest chelating solvent a high pH for the removal of iron oxide scale from utility boilers. Dequest compounds are currently used by Halliburton in an acid process for removing iron oxide scale from ferrous surfaces under the name “Alkleen.” The Alkleen process operates at a pH between 4 to 7 and at temperatures between 150° and 175° F. The Alkleen acid process is used by Halliburton for dissolving iron oxides, but is not used in competition with Dow’s Vertan 675 ACR Process in the cleaning of utility boilers. G. Defendant Halliburton’s MACOR Process Halliburton adopted the name MACOR, an acronym for MA genite-CO pper-f? emoval, for its alkaline ammonium EDTA solvent cleaning process in about 1975, and on occasion has applied the name MACOR to a process for removing iron oxide only. The first use by Halliburton of the MA-COR process alleged to infringe claim 6 of the Lesinski patent occurred on May 16, 1977, at Pennsylvania Power and Light Company, and removed only iron oxide from the. boiler ferrous surfaces. In that job, the procedures employed were those of the MACOR field bulletin then in effect, except that the MACOR concentrate that was used did not contain hydrazine, a chemical reducing agent, and no nitrite or air blow was used to achieve passivation. The boiler had to be drained as a result of formation of precipitates caused by a shortage of EDTA. Halliburton considered the cleaning successful. The MACOR process employs the same steps that are used in removing iron oxide with Dow’s Vertan 675, including preparation of an aqueous ammoniated EDTA solution having a concentration of about 39.5% and pH of about 9. The concentrate is injected into a boiler to be cleaned to produce a diluted solution of about 5-10% ammoniated EDTA in the boiler, and the temperature is raised to the range of 250° to 275° F. The solution is circulated through the boiler and contacted with the scale on the boiler tube walls and on other ferrous surfaces to remove the iron oxide scale. At the completion of the iron oxide step, the temperature of the EDTA solution is cooled to about 150°, the solution is adjusted to contain up to 1% free EDTA in the form of its ammonium salt, sodium nitrite is added, and air is injected and continued until the copper is dissolved and the ferrous boiler surfaces are passivated. The injected air and the added sodium nitrite both perform the same functions, viz., they are used to oxidize the iron chelate of EDTA for copper removal. During the copper removal stage, the degree of spetness, i.e., the ratio of iron-complexed chelate over the sum of the free chelate and the iron-complexed chelate is maintained at about 75%. The MACOR solution is brought on the job in a concentrated form containing about 39.5% EDTA and is put into the boiler and diluted. The concentrate has a pH of 9 at room temperature but when injected into the hot boiler has a pH below 8. A MA-COR Technical Data Sheet stated that the MACOR service removes scale from heat exchange surfaces at a pH of 9 and at a temperature of 240° to 275° F. Halliburton’s Bradley admitted that the MACOR process “primarily follows the teachings of the Lesinski and the Harriman patents.” Shortly after March 1977, when Halliburton reversed its prior stance and authorized Halliburton field salesmen to solicit ammoniated EDTA boiler cleaning jobs, Halliburton salesman Stewart obtained from Metropolitan Edison in Reading, Pennsylvania, a copy of Dow’s Vertan 675 ACR Process procedure on an earlier cleaning of the Titus No. 2 boiler, and forwarded the procedure to Dr. Frost in Duncan, Oklahoma, stating “here is some good information that I feel we could use as a guide in our first few MACOR projects.” In October 1977, Halliburton cleaned the Metropolitan Edison Titus Boiler No. 1 at Reading, Pennsylvania. The procedures used were substantially the same as those set forth in Dow’s earlier Vertan 675 ACR cleaning of the Titus No. 2 boiler, except that Halliburton added sodium nitrite to air for oxidizing during the copper removal stage. On another occasion, Halliburton took a copy of the Dow 675 ACR Process specification for an earlier job and merely crossed out the name “Vertan” and substituted “MACOR” and crossed out “Dow Industrial Service” and inserted “Halliburton Services” as supplier of the exact materials and procedures specified in the earlier Dow job. The MACOR process is in fact a copy of Dow’s Vertan 675 ACR Process, and in all material matters the field procedure for each is the same. V. THE ’065 LESINSKI PATENT A. The ’065 Invention The ’065 patent teaches a method for chemically removing iron oxide scales from metal surfaces, such as the interior walls of the tubes in a steam generating utility boiler, by the use of an alkaline aqueous solution of an ammonium salt of EDTA at a pH of 8 to 11. The ’065 patent is based on the discovery by Chester Lesinski on February 17, 1961, that aqueous alkaline solutions of ammonium EDTA having a pH of about 9 will dissolve iron oxide scales from a metal surface whereas the aqueous solution of the sodium salt of EDTA at the same pH will not dissolve the same iron oxide scale at nearly as fast a rate under the same conditions as shown in Examples 2 and 3 of the specification. Lesinski’s formal education consisted of one year in junior college and one year in pharmacy school at the University of Michigan. He joined Dow approximately twelve years prior to his invention disclosed in the ’065 patent. Lesinski worked as a chemist for Dow prior to 1960, and in 1960-61 he conducted research relating to processes for scale removal from metal surfaces. Prior to moving from Midland, Michigan, to Cleveland, Ohio, to work in the Dow Industrial Service (DIS) laboratory, he conducted a trial cleaning job at Fisher Body Division of General Motors in Pontiac using an acid solution of sodium EDTA at a pH of 6 to dissolve operational scale deposits from a welder water cooling system. During that job, leaks developed in the piping because of corrosion, nearly causing a plant shutdown. After that experience, Lesinski maintained an interest in developing an alkaline chelating solution which would be less aggressive toward metal. In Cleveland, he did some work with sodium salts of EDTA, and knew that sodium EDTA at an alkaline pH was inefficient in removing iron deposits. He also did some work with addition of chemical reducing agents to sodium EDTA solutions to see if he could accomplish the dissolution of iron oxide scales at alkaline pH. Having that background, Lesinki listened to a presentation in the laboratory of the DIS Cleveland group by Dr. Gordon Bell of the Charles Pfizer Company, who discussed dissolving iron oxide scales with acid solutions of ammonium citrate using Pfizer’s then new Citrosolv process. Dr. Bell described a two-stage process. The first stage involved using an ammoniated citric acid solution at an acid pH of 3 to 5. The second stage involved adjusting the pH to an alkaline range with ammonia. Dr. Bell did not mention the use of neutral or alkaline citric acid solutions for use in dissolving iron oxide. During Dr. Bell’s presentation, Lesinski realized that he had never tried the ammonium salt of EDTA to dissolve iron oxide scale. Lesinski went back to his laboratory, prepared a solution of Versene acid (EDTA) and water by mixing ammonium hydroxide until the pH stabilized at around 9. He took sections of boiler tube available in the laboratory to a local machine shop and had them cut it into short lengths of about 8 inches. He then inserted one of the tubes in a beaker containing the test solution and brought the solution to boiling on a hot plate. He smelled ammonia evolving, and periodically added ammonium hydroxide to maintain a pH of 9. He noted fast dissolution of the black scale on the inside surface of the tube, and after about a half hour of boiling, found that it was clean bare metal. After flushing the tube with water and air drying, he noted that there was no after-rust visible on the clean section, although the unsubmerged top section of the tube still contained the operational deposits. The boiler tube test was performed by Lesinski on February 17, 1961, and was recorded in his handwriting in his notebook. On February 24, 1961, Lesinski performed in the Cleveland DIS laboratory the scale dissolving tests that appear in the ’065 patent as Examples 2 and 3. Example 2 was run using ammoniated EDTA solution at a pH of 9 by placing a laboratory scale sample, most magnetite, Fe304, in the solution, raising the solution to a boiling temperature, and maintaining boiling for three hours, during which time periodic additions of ammonium hydroxide were made to maintain the pH at about 9. Lesinski used the same procedure of adding ammonium hydroxide during the boiling of the scale sample in Example 2 that is reported in his notebook. Example 3 was performed using the same procedure as described for Example 2 except that the scale sample was mostly hematite, or red iron oxide, Fe203, that was available to him in the laboratory. The details of Examples 2 and 3 were recorded in his handwriting in his notebook under the date of February 24, 1961, and record the actual results which he obtained at that time. In June 1961, Lesinski returned to his laboratory job in Midland. In July or August of 1961, he assisted in the experimental cleaning job of the Dow boiler at Midland using ammoniated EDTA solution at a pH of 9, helping with the analytical work. Lesinski then assumed other duties with Dow and has not worked further in the field of chemical cleaning. B. Level of Ordinary Skill in the Chemical Cleaning Art The art is broadly the field of chemical cleaning, and one of ordinary skill in that art has general familiarity with inorganic and organic chemicals known to have ability to dissolve metal, some practical experience or knowledge of commercial cleaning and metal scale removal operations, such as removing rust, hardness scale, iron and copper deposits from metal surfaces, and the like. Such a person may have but does not necessarily have, a college degree in chemistry or related science, and does not necessarily possess a high level of theoretical understanding of the mechanisms of dissolution of metal scales, or passivation, or corrosion of metal surfaces, but does have knowledge of previously used cleaning chemicals and processes. C. Scope and Content of the Prior Art Prior to the date of filing of the original Lesinski application, EDTA, a polycarboxylic acid, was recognized as the best and most versatile of the chelant. It was known that divalent ions, including ferrous ions (Fe+ +), were readily chelated at alkaline pH with EDTA, whereas trivalent ferric ions (Fe+ + +) presented difficulties. Also, at highly alkaline pH, ferric ions tended to precipitate from EDTA solution. EDTA had been used to chelate copper, iron, calcium, zinc, lead, nickel, and cobalt. The ability of EDTA to form chelate complexes with metal ions was known to be a pH-dependent phenomenon, and chemical cleaning with EDTA had been conducted at various pH’s in an attempt to optimize the rate of dissolution. Prior to the Lesinski invention, sodium EDTA had been used successfully to remove iron scale from boilers and similar devices such as engine cooling systems and sugar evaporators, but at alkaline pH of about 9 and above, added reducing agents such as dextrose sugar or sodium sulfite were used to convert ferric ions to more easily chelated ferrous ions. The problem of precipitation of ferric complexes from EDTA solutions at pH 8-10 also could be overcome by adding a reducing agent to the solution. The prior art contemplated the equivalence of sodium, potassium, or ammonium EDTA in chemical cleaning. It was also known that the addition of ammonia to raise the pH of an EDTA solution containing complexes of di- and trivalent metals, other than iron (III) would not induce precipitation; that in an iron (III)— EDTA system, precipitation occurs in basic solution and that EDTA is an effective complexing agent for iron (III) only in acidic or neutral solutions. The Citrolsolv process disclosed in Pfizer’s U.S. Patent 3,072, 502 to Alfano, and his October 1961 publication, are included in the prior art. As noted earlier, the Citrosolv process employs ammoniated citric acid (CA), a polycarboxylic acid. CA and EDTA both are organic acids having multiple acid groups (CA has three, EDTA has four), which in solution can form complexes, or chelates, with metal ions that keep those ions in a dissolved or “sequestered” state. Both materials had been used to chelate copper and iron. While EDTA is a better chelant because it forms stronger complexes, and is more versatile than CA, this was generally recognized long prior to the alleged Lesinski invention. Both chelants had been disclosed for use in chemical cleaning to remove iron scales prior to the Lesinski invention. The Citrosolv process, however, involves the use of a solution of CA ammoniated to a pH of 3 to 4 and heated to about 200° F to dissolve magnetite, followed by cooling the solution to 150° F, raising the pH to 9.5 to 10 by the addition of ammonia, and then adding .5% sodium nitrite generally combined with intermittent air sparging to oxidize and remove copper. The Citrosolv process thus differs from both the Vertan and the MACOR process using ammoniated EDTA in that it requires a change in the cleaning solution from acid to base, i.e., from a pH of 3.5 to 4 to a pH of 9 to 10, when the process is employed to remove both iron oxide and copper scale. The process also employs chemicals such as ammonium carbonate, and sometimes ammonium bifluoride, not employed with EDTA. Furthermore, ammoniated CA at alkaline pH is not effective to dissolve boiler tube iron oxide scale, and while it will dissolve scale at neutral pH, it is not practical for such and has not been used to clean utility boilers at neutral pH. . The Citrosolv process thus gave those skilled in the art a reason to prefer ammoniated EDTA chelants over other types of chelants in a process which dissolves iron oxide from a metal surface at acidic pH, with the solution pH then adjusted to the alkaline range to dissolve copper. The pri- or art teaching that ammonia added to EDTA would not precipitate divalent or trivalent ions at highly alkaline pH was confined to the complexation of trivalent ions other than iron (III) and gave those skilled in the art no reason to prefer ammoniated EDTA chelants over sodium EDTA chelants which were known to be capable of dissolving iron oxide scale at an alkaline pH only in the presence of an added reducing agent. D. Contemporaneous Teachings The Mamet-Vlasova Russian article published in November 1962 reported the results of tests and investigations in boiler cleaning primarily with regard to magnetite iron scale removal with chelants. EDTA, sodium EDTA, ammonium EDTA, CA, and ammoniated CA are all discussed and used in the tests. The article states that of these chelants, EDTA neutralized with ammonia shows the highest ability to dissolve iron oxide scale. The article states that the optimum pH for sodium EDTA solutions and ammoniated CA solutions is 4, and that pH of the sodium EDTA solution may be raised to 8-9 to protect against corrosion; it further states that “[t]he possibility of raising the pH-value of citrate solutions is not yet clear.” Use of ammoniated EDTA at alkaline pH is not discussed. The teachings of the article regarding use of ammoniated EDTA at alkaline pH, if any, are so abstruse as to be useless, and clearly do not reflect Lesinski’s invention. The Bell U.S. Patent 3,248,269 filed August 15, 1962, entitled “Scale Removal,” presents a contemporaneous disclosure that ammoniated CA at neutral and alkaline pH can be used to dissolve iron oxide scale. As noted earlier, however, this process in fact is not effective at alkaline pH, and, at neutral pH, will not dissolve scale in a commercially feasible manner. E. Claim 6 of ’065 Patent (Claim 6 of Re. 30,796) A process for removing (1) hardness scale and one or more iron oxide-containing deposits of the group of Fe203-containing and FesOr-containing deposits or (2) one or more iron oxide-containing deposits of the group of Fe203-containing and FesOi-containing deposits (3) from a metal surface containing one or more of the aforesaid hardness scale and iron oxide-containing deposits (4) by contacting said metal surface with an aqueous alkaline saline solution having a pH of 8 to 11, the active ingredient of which consists of at least one salt of the group consisting of ammonium ... salts ... of alkylenepolyamine polycarboxylic acids ... wherein the alkylenepolyamine polycarboxylic acid salt of the alkaline saline solution employed is a salt of an acid of the formula (H00CCH2)2N[Ch2)nNCH2C00H]mCH2C00H wherein n is 2, m is 1 (5) for a time sufficient to dissolve said hardness scale and said iron oxide-containing deposits. Ammoniated ethylenediamine tetraacetic acid (EDTA) is a salt which is covered by the formula, and is the compound when m is 1 and n is 2. F. Prosecution History of Lesinski ’065 Patent The prior art known to the Patent Office and relied on before claim 6 was allowed on November 30, 1966, appears in the file history of the parent application filed July 23, 1962, and in the continuation-in-part application (CIP) filed July 22, 1963. The original claims in the 1962 parent application and the CIP were broader than the claims which appear in the ’065 patent. In the only office action on the parent application, the Patent Office rejected all claims on two Bersworth patents and a 1952 publication by Geigy Industrial Chemicals entitled “Sequestrene.” Bersworth I, U.S. Patent 2,396,938, taught, in 1946, an alkaline solution consisting of sodium and potassium EDTA salts and a basic material for removal and prevention of scale formation in water boilers. The Sequestrene catalog taught that ammonium and alkylolamine salts of EDTA are old, and that EDTA generally is well suited for treating water systems. Bersworth II, U.S. Patent 2,544,649, issued in 1951, was relied on for showing the combination of an alkanolamine and salts of EDTA, or EDTA, in treating water systems. In its first action in the CIP application, the Examiner noted that claims 1-9 were of the same scope as the claims in the parent application and rejected all of them on the same prior art as in the parent application. Dow then amended the claim from one requiring ammonium EDTA as “an essential constituent” to one wherein the active ingredient “consists of” ammoniated EDTA. Also, Dow attempted to distinguish the claims on the basis that the claimed invention uses amine salts of EDTA, not alkali metal salts, to dissolve “an otherwise insoluble scale,” whereas Bersworth I requires two salts, neither of which was an amine salt, or one alkali metal salt and a free base, and the Sequetrene publication showed amine salts of EDTA but mentioned no uses for them, while Bersworth II showed alkali metal salts to inhibit precipitation of metal ions in solutions but contained no teaching concerning dissolving scale deposits and iron oxide deposits from a metal surface using amine salts of EDTA. Dow attempted further to distinguish the claims on the basis that alkali metal salts of EDTA are ineffective to remove iron oxide scale at pH greater than 8, and on the basis that while the Sequestrene publication taught that EDTA and its salts would remove rust and tarnish when used with added reducing agents, its process did not use an added reducing agent. The Patent Office rejected Dow’s distinctions and gave a final rejection of all of the claims, relying on the Sequestrene publication for metal cleaning uses, and the fact that alkaline solutions for preventing scale were old, to find that it would be obvious to one skilled in the art to combine the references to form the claimed composition. Dow then appealed the Examiner’s rejection to the Board of Appeals. Dow argued to the Board of Appeals that the term “Sequestrene” referred to EDTA acid, and that while the Geigy publication offered the sodium salt of EDTA, ammonium EDTA salts were not offered, and the publication mentioned no use for ammonium salts. Additionally, Dow argued that alkaline metal salts of EDTA are unable to dissolve iron oxide deposits at alkaline pH, or to achieve inherent passivation. Dow also presented the Lesinski affidavit, and argued to the Board that the affidavit supported “the unusual and unexpected results” obtained with ammonium EDTA salts relative to alkali metal salts at a pH of 9. In response to Dow’s brief on appeal, the Patent Office dropped its prior rejections, reopened prosecution on the basis that a clear issue had not been reached, and rejected claims 1-8 on three newly cited references. The Examiner relied on Flaxman, U.S. Patent 2,802,788, issued in 1957, as anticipating claims 1, 2, and 5-7, including claim 6 of the ’065 patent in issue. The Examiner relied on Yonkman, U.S. Patent 1,523,741, issued in 1925, for teaching ammonium citrate to dissolve rust from a metal surface and thereafter rinsing, taken in combination with Flaxman, to make claims 3 and 4 obvious. Claim 8, a method of passivating with amine EDTA salts was rejected as anticipated by Arensberg, U.S. Patent 3,099,521, issued in 1963, and Tucker, U.S. Patent 2,264,103, issued in 1941. The originally submitted Lesinski claims required merely an “alkaline” pH as opposed to one within the specific alkaline range of 8-11. Also, both the parent and continuation-in-part Lesinski applications disclosed ammoniated CA as being the equivalent of ammoniated EDTA, and claimed the use of ammoniated CA at alkaline pH as Lesinski’s invention. In response to this rejection based on prior art, Dow’s claims were narrowed to exclude CA, to exclude processes in which the solvent was contacted with the scale at a pH other than 8-11, and to exclude specifically processes in which a reducing agent was added. Dow also defined the scale as hardness scale, or iron oxide scale, or both. With respect to Flaxman, Dow argued that Flaxman teaches removing iron rust and other oxides from cooling systems of automobiles with a solution having four required constituents: a grease emulsifier; a reducing agent such as sodium bisulfite; an inorganic sequestering agent such as sodium tripolyphosphate; and sodium EDTA, or alternatively, an amine salt of EDTA. Dow attempted to further distinguish Flaxman as to pH, arguing that Flax-man taught use of solutions at pH’s below 8 because the solution at pH above 8.5 was too slow to be practical for removal of iron rust. Dow also attempted to distinguish Flaxman on the basis that in Dow’s claims, no reducing agent is necessary, meaning, in context, no added chemical reducing agent such as sodium bisulfite. Dow sought to differentiate Yonkman on the basis that it relates to acidic ammonium citrates, and should not be combined with Flaxman due to pH differences. Dow argued against Arensburg and Tucker urging that they address prevention of scale and precipitation of hardness scale, rather than dissolution of scale. The Patent Office rejected Dow’s argument over Flaxman and Yonkman, but entered Dow’s amendment for purposes of appeal, and Dow appealed a second time and filed a brief. The Examiner reversed his position without explanation, allowed all of the claims, and the ’065 patent issued on March 7, 1967. G. Prosecution History of the Lesinski Reissue On September 9, 1978, Dow filed an application to reissue the ’065 patent in order to obtain consideration of prior art identified by Halliburton in its July 1978 answers to Dow interrogatories Nos. 1-23, and consideration of other information not previously considered by the Patent Office. The reissue was sought under 35 U.S.C. § 251 and Patent Office Rules, 37 C.F.R. §§ 1.171-1.179, that were amended in 1977 under the direction of then-Commissioner of Patents Dann. Under the amended rules, reissue could be requested without admitting the original patent was partially invalid, and such was Dow’s allegation with respect to claim 6, the claim in issue here. In the application, Dow filed a copy of Halliburton’s answers to Dow interrogatories 1-23, a list of Halliburton’s privileged documents, copies of three Halliburton attorney opinions of invalidity of the ’065 patent, and Halliburton’s answer and counterclaim. In addition, Dow brought to the attention of the Patent Office with the filing of the reissue patent application that prior art which it considered most relevant to the claimed invention. This art included the patents cited during the prosecution of the ‘065 patent, seven of the references cited by Halliburton in their answers to Dow’s interrogatories, and eleven other patents or references which Dow considered relevant. In the first office action, Examiner Albrecht cited many of the references identified in Halliburton’s answers, including Bersworth and Singer U.S. Patent No. 3,033,214, publications identified by Dow, including the Mamet-Vlasova Russian publication, and patents not called to his attention by Dow that were located in his own prior art search. He rejected claim 7 directed to the method of passivating a ferrous metal surface on the basis of Flax-man, Arensberg, and a reference identified by Halliburton. After obtaining a copy of the Russian reference, he ruled that the effective date against prior art of claim 6 is July 23, 1962, and that the Russian reference published in November 1962 is not prior art to claim 6; he similarly ruled that Bell U.S. Patent No. 3,248,269 is not prior art. In deciding that there was invention in claims 1-6, Examiner Albrecht stated: Claims 1-6 have not been rejected on prior art grounds over Bersworth VI either alone or in combination with any other of the prior art references of record because of the affidavit filed during the prosecution of the parent application. The striking superiority of the ammonium salt over the corresponding sodium salts in removing iron oxides in the recited pH range as well as hardness scale is not only unobvious, but is extremely desirable in the art and solved a serious problem in the industry. Neither Bersworth VI (3,033,214) or any of the other prior art references suggest that the recited ammonium or amine salts would be so strikingly superior to the corresponding sodium salts in this respect at the recited pH range. In rendering his decision, the Examiner thus heavily relied upon the results set forth in the Lesinski affidavit which had been submitted during the prosecution of the ’065 patent. During prosecution, Examiner Albrecht suggested to Dow’s counsel Kanuch that Halliburton should be a party to the reissue proceedings and that he was interested in Halliburton’s interpretation of the prior art. The examiners and other officials of the Patent Office requested that Dow keep the office informed of the status of this litigation and keep it apprised of “any and all defenses” asserted by Halliburton, and the “reasons for Halliburton’s belief that some or all of the instant claims may be unpatentable under 35 U.S.C. 102 or 103.” Assistant Commissioner Tegtmeyer stated that “Applicant is required to keep the Office advised of the status of these civil actions ... and to submit to the Office any information developed therein, or in relation thereto, which is material to the examination of this application.” Even though Assistant Commissioner Tegtmeyer formally invited Halliburton to protest under 37 C.F.R. 1.291, Halliburton did not formally protest nor attack claim 6, except by way of voluntarily advising Examiner Albrecht about the “relevant, correct” opinions of invalidity of the ’065 patent on the day prior to Kanuch’s first interview with Examiner Albrecht on A