COMMISSIONER'S DECISION
OBVIOUSNESS: Dohalogenation Process
Some claims of this application, which related to the conversion of
metal halides were refused for failing to define a patentable advance
in the an over the reference cited. The rejection against claim 19
was withdwawn.
Final Action: Affirmed in part.
This decision deals with a request for review by the Commissioner of
Patents of the Examiner's Final Action dated May 27, 1975, on applica-
tion 126,631 (Class 23-224). The application was filed on November 2,
1971, in the name of Leonard N. Brigham et al, and is entitled "Dehalogen-
ation Process."
The general subject utter of this invention is the conversion of metal
halides, represented by MX4, to the corresponding oxides MO4. To accomplish
this by prior art processes using hydrogen as the dehalogenating agent
re~~ired temperatures in excess of 2000øF, The use of such high temperatures
produceu oxide powders with less than optimum surface characteristics. The
present inventors disclosed that they could convert oxyhalides, represented
by MO2X2, to MO4 at temperatures from 600øF. to 1600øF. using a vapourized
alcohol as a dehalogenating agent and subsequently filed a supplementary
disclosure widening the scope of the materials treated from oxyhalides to
halides in general.
In the Final Action the examiner refused claims 13-18 and 20-23 of the
supplementary disclosure for lack of invention in view of the following
United States Patent:
3,000,703 Sept. 19, 1961 Brugger
Claim 19 was also refused on the ground of lack of support in the disclosure.
In that action the examiner stated (in part):
Applicant, in his letter of February 3, 1975, has argued against
the relevance of United States patent 3,000,703 as applied in the
rejection of claims 13 to 18 and 20 to 23 because he alleges
that there are significant differences between the present in-
vention as set forth in revised claims and the prior art.
The first "difference" discussed by the applicant relates to
the surface area and the bulk density of the zirconia product formed
by the dehalogenation reaction, Applicant's specification teaches
on page 2 lines 2 to 30 "To dehalogenate a metallic oxyhalide such
as uranium oxyfluoride one needs, when using hydrogen, a temper-
ature in excess of about 2000.degree.F to have a practical rate of
dehalogenation. Such a temperature produces undesirable properties
in the resulting ceramic including the loss of the ability to
make dense compacted ceramic bodies from the resulting powder
due to a deadening of the powder (loss of surface area of the powder)
at the temperature required for the dehalogenation process. In
order to lower the temperature for conducting successful dehalogenation
of metallic oxyhalides a wet hydrogen atmosphere has been used which
has the effect of increasing the rate of dehalogenation at any
given temperature when compared to the use of dry hydrogen. This also
has a practical effect of lowering the temperature needed to achieve
a practical rate of dehalogenatien of a metallic oxyhalide. The
dehalogenation process using wet hydrogen gives economies of
operation and an increased powder activity in that there is greater
ability of the powder to be compacted and sintered to dense structures.
In spite of the foregoing, it has still remained desirable to lower
the temperature for achieving a practical, rapid rate of dehaiogenation
of metallic oxyhalide containing compositions. The lower temperature
of dehalogenation of metallic oxyhalides enables even greater powder
activity, enables greater economies of operation arid gives more dense
structures after the powders are compacted and sintered." And on
page 6 lines 10 to 31 "While any temperature achieving dehalogenation
can be employed by utilizing heated furnaces receiving the alcohol-
containing atmosphere, the temperature is generally under about 1600øF
and preferably under about 1100.degree.F where it is desired to have a powder
of high surface area with the range of temperature being about 600 to about
1600øF and a preferred range of temperature being about 600 to
about 1100øF. This range gives a rapid rate of dehalogenation while
preserving high surface area of the deh alogenated powder. In general
the higher the temperature used the greater the rate of dehalogenation
achieved with greater hydrocarbon impurity content of the dehalogenated
powder. The lower temperatures in the foregoing range give the
highest surface areas for the defluorinated powder. Where the
atmosphere used in the furnace contains only vaporized alcohol, a higher
temperature up to about 1600øF can be utilized for the dehalogenation
step without loss of activity of the dehalogenated powder with a
particularly preferred range of temperature being about 1200 to
about 1600.degree.F. Again the rate of dehalogenation and the surface area of
the dehalogenated powder vary with the particular temperature in the
foregoing range as noted above."
Both of these quotations indicate that low temperatures for the
dehalogenation reaction promote the formation of products of high
surface area and high bulk density. Thus, the Brugger process, which
recommends the use of lower temperatures than those of the instant
specification, should result in the production of high surface area,
high bulk density oxide products. The Brugger teaching con-
firms this contention in column 1 lines 9 to 11, column 2
lines 3 to 34, column 2 line 65 to column 3 line 7 and column 5
lines 51 to 55 of the patent. Each of the specified passages
refers to a method of obtaining a high-purity zirconium oxide
having a high bulk density in a porous granular form, ideal for
making refractory objects as well as for use in the ceramic and
glass industry, and thus precisely the type of product applicant
desires to obtain.
The applicant in his response dated August 15, 1975, to the Final
Action stated (in part):
The Brugger reference is directed to a two-step method of conversion
of a halide to an oxide, and is limited in its teaching to a
particular halide compound, namely zirconium tetrachloride.
Brugger's process involves heating in the presence of a hydrolysing
agent, follotued by a calcination step conducted at a substantially
higher temperature than the hydrolyzing step.
A two stage heating cycle is not employed in the subject invention.
In the matter of rejection of claim 19, attention is directed
to page 7 lines 5 through 11, which deals with the dehydration
step referred to by the Examiner.
So far as application of the Brugger reference is concerned,
attention is drawn to the case Canadian General Electric Co. Ltd. v
Fada Radio Ltd. 1927 Supreme Court Report (SCR) 520 "....The true
construction of a patent specification must be based on the
specification alone, to derive the intentions of its authors...."
Also "....Any information as to the alleged invention given by any
prior publication must be for the purpose of practical utility
equal to that given by the subject patent." In the foregoing,
for "patent" substitute --application--.
The Brugger reference shows the conversion of zirconium chloride to zirconium
oxide by heating the zirconium chloride in the presence of a vapourized
alcohol. The temperature range taught by Brugger is based on the practical
considerations which would appear necessarily to apply to anyone carrying out
this reaction: high enough to maintain the alcohol in the vapour state and
low enough to prevent excess loss of the halide through volatilization. More
specifically he describes a method of dehalogenating zirconium tetrachloride
comprising the step of heating the halide at temperatures in the range from
about 120øC to 1200øC (248øF to 2192øF) in a dehalogenating atmosphere
having as the dehalogenating component a vaporized alcohol.
Brugger also describes certain inherent advantages including: (a) the
potential for employing loner dehalogenation temperatures than those recorded
for other prior art processes; (b) the retention of active surface character-
istics on the metal oxide product; (c) the production of a high purity, high
density product which can easily be processed into highly refractory articles
or structural material; and (d) the recovery of a highly concentrated hydro-
halic acid by-product which are attainable through the use of a vaporized
alcohol dehalogenation agent. These specified advantages correspond
substantially to the desired objectives of the inventors of the instant
application.
Claim 1 of the Brugger citation reads as follows:
A process for the production of zirconium oxide which comprises:
(a) introducing solid zirconium tetrachloride into a reaction
zone,
(b) simultaneously introducing into the reaction zone a hydrolyzing
agent,
(c) said hydrolyzing agent having the formula ROH wherein R is selected
from the group consisting of hydrogen and alkyl radicals containing
between one and five carbon atoms,
(d) maintaining the temperature in the reaction zone above the boiling
point of the hydrolyzing agent but below the sublimation point of
the zirconium tetrachloride,
(e) maintaining the said reactants in the reaction zone for from about
1-5 hours in order to substantially eliminate the chloride from the
resulting zirconium oxide product, and
(f) thereafter calcining the resulting product to convert hydrous zirconia
to zirconium oxide.
This application relates to the conversion of metal halides represented by MX4, to
the corresponding oxides MO4 at temperatures from 600øF to 1600øF using a vapor-
ized alcohol as a dehalogenating agent. A supplementary disclosure was filed to
broaden the scope of the materials treated from oxyhalides to halides in general.
Claim 13 (supported by supplementary disclosure) reads as follows:
A method of dehalogenating a composition including a metallic halide
wherein the metallic portion is selected from the group consisting
or uranium, plutonium, titanium, zirconium, silicon, tungsten, gado-
linium, aluminum and mixtures thereof comprising the step of heating
the composition at a temperature in the range of about 600øF to
about 1600øF in a dehalogenating atmosphere having as the dehalogenating
component a vaporized alcohol.
The question to be considered is whether claims 13 to 18 and 20 to 23 are
too broad in scope in view of the Brugger citation.
We observe that the Brugger reference is restricted in its teaching to the
dehalogenation of zirconium tetrachloride for the production of zirconia,
whereas this application relates to the dehalogenation of metallic halides in
which the metallic portion is selected from the Markush group consisting of
uranium, plutonium, titanium, zirconium, silicon, tungsten, gadolinium,
aluminium and mixtures thereof. The metallic halides encompassed by the
applicant's claimed processes have a wide range of physical and chemical pro-
perties and under conditions of dehalogenating may require non-uniform pro-
cessing techniques to assure the retention of desirable surface characteristics
on the metal oxide products. These possible anomalies are not disclosed in
applicant's specification but the adequacy of the supplementary disclosure
for the support of the presently rejected claims was not challenged since
it has been made evident that in the course of preparing a pure uranium oxide,
the dehalogenating technique employing alcoholic reagents, utilized in the
process of the principal disclosure for the dehalogenation of metal oxyhalides,
was also found effective to dehalogenate the metallic halides of claim 13.
The single example included in the supplementary disclosure describes to a
highly restricted embodiment wherein the halides are present only in trace
amounts. No teaching of particular temperature conditions or handling
requirements specific to the treatment of the various metallic halides has
been supplied. It is therefore clear that the only possible invention
encompassed by the refused claims rests entirely in the selection of a vapor-
ized alcohol to serve as the active agent in a dehalogenation reaction. This
festure, however, is obvious in view of the Brugger citation.
The applicant, in his response to the Final Action, has relied upon the
apparent difference in the defined dehalogenation temperature to distinguish
the processes of the rejected claims from the teaching of the reference.
However, it is observed that the main thrust of applicant's disclosure
relates to the development of a dehalogenation process which operates at
temperatures sufficiently low to avoid producing undesirable surface
characteristics in the resulting ceramic product. This desired improvement
was effectively achieved through the use of low initial reaction temperatures
in the process described by the Brugger patent. Furthermore it may be
reemphasized that once the sublimation temperature of the partially de-
halogenated zirconium chloride was sufficiently elevated to prevent any
significant loss of zirconium tetrachloride through volatilization, the
reaction temperature in the Brugger process was raised to a range from about
500·. to 550.·C. (932·F. to 1022·F.) for the completion of the reaction.
This value lies within the range of useful temperatures defined by rejected
claim 13.
The applicant argued that "a two stage heating cycle is not employed in the
subject invention." We note, however, that Brugger shows all aspects of the
process of converting ZrCl4 to ZrO4 taught by the present applicant. The
one stage heating cycle is not, in our view, patentably significant over a
two stage heating cycle in the present circumstances.
The applicant relied upon a Supreme Court decision, Canadian General Electic
Co. Ltd. v Fada Radio Ltd, and quoted a passage from it to support his
argument against the refusal of certain claims. The passage, however, "....
Any information as to the alleged invention given by any prior publication
must be for the purpose of practical utility equal to that given by the
subject patent," does not appear in that case. It is, however, in The King v
Uhlemann Optical Company (1950) Ex. C.R. 142 at 157 where we find: "The requirements
that must be met before an invention should be held to have been anticipated
by a prior publications have been discussed in many cases and may be stated
briefly. The information as to the alleged invention given by the prior
publication must, for the purpose of practical utility, be equal to that given
by the subsequent patent." (underlining added) It is clear, however, that
the court was concerned with anticipation and not with obviousness or lack of
invention. Notwithstanding the above, the Brugger citation does describe a
process for the dehalogenation of zirconium tetrachloride to yield zirconium
oxide. The patented technique has a practical utility substantially equal to
that of the process in refused claim 13, which process encompasses the same
reaction for the same purpose.
We are satisfied that the similarity of the process defined by claim 13 to the
teaching of the Brugger citation makes it clear that there is no patentable ad-
vance made in the art. The remainder of the refused claims, namely claims 14
to 18 and 20 to 23, which are essentially dependent on claim 13, contain minor
restrictions which are not deemed inventive.
It is also noted that claim 19 was refused for lack of support in the disclosure.
The claimed embodiment is, however, supported by the disclosure on page 7,
lines 5 through 11. That rejection is therefore withdrawn. It is noted that
this claim should appear with those claims supported by the principle disclosure
rather than under the heading "Claims Supported by Supplementary Disclosure."
We recommend that the decision in the Final Action to refuse claims 13 to 18 and
20 to 23 be affirmed, and that the ground for refusing claim 19 be withdrawn.
Claim 19 should therefore be renumbered "claim 13."
J.F. Hughes
Assistant Chairman
Patent Appeal Board
I concur with the recommendations of the Patent Appeal Board. Accordingly, I
refuse to grant a patent on claims 13 to 18 and 20 to 23. The ground for the re-
jection against claim 19 is withdrawn. The applicant has six months within which
to submit an apprppriate amendment cancelling the refused claims, or to appeal
this decision under the provision of Section 44 of the Patent Act.
J. H. A. Gari‚py
Commissioner of Patents
Dated at Hull, Quebec
this 3rd. day of May, 1976
Agent for Applicant
R.A. Eckersley,
214 King St. W.,
Toronto 1, Ont.