COMMISSIONER'S DECISION
INSUFFICIENT DISCLOSURE: Claims Too Wide.
The specification taught a process using catalysts which
rupture during polymerization, achieved by supporting the
catalyst upon a porous carrier. The use of porous catalyst
supports was prior knowledge. The claims were refused since
only silyl chromate catalysts were mentioned in the disclo-
sure. It was held that it would be obvious to skilled
chemists that this procedure could use other catalysts and
porous carriers to produce the required result.
FINAL ACTION: Reversed.
**************************
This decision deals pith a request for review by
the Commissioner of Patents of the Examiner's Final
Action dated March 27, 1972 on application 028,123.
The application was filed on August 21, 1968, claming
a priority of August 21, 1967. The applicant is the
Union Carbide Corporation, the inrentor Adam R. Miller,
and the title of the invention "A Continuous Process
for the Production of High Molecular height Polymers
of Olefins by Employing a Particulate Catalyst." The
applicant filed a written response to the rejection,
and specified that no oral hearing was requested.
In his rejection the examiner refused two claims, 20 and
25, as being indefinite and too broad for the disclosure.
Claims 21-24 and 26-30 would also fall, since they are
dependent on either claim 20 or claim 25. Claims 1-19
and 31 to 40, howerer, were not refused.
The invention relates to an improved method for polymerizing
olefins, and to apparatus used for that process.
Heretofore the polymerization had been carried out in
the vapour phase using fluidized catalysts, such as
hexavalent chromium oxide catalysts, but one problem
has been corrosion produced by the catalysts. Another
difficulty relates to contamination of the product with
the catalyst used.
By using a silyl chromate catalyst, the applicant has
overcome some of these problems. The catalyst residue,
for example, is non corrosive. He uses the catalyst in
a special reactor, one feature of which is the presence
of a gas distribution plate. This plate permits the
applicant to keep the reaction area fluidized by recycling
gas through the distribution plate into the reaction zone.
By injecting the catalyst above the distribution plate,
the polymers desired are formed only above the plate, and
will not clog it. These features form an essential part
of the improved process covered by process clams 1-4,
10-13, 18, 19 and apparatus claims 31-40.
The applicant has also disclosed a second improvement.
If he supports the silyl chromate catalyst (and according
to the applicant other catalysts) open certain porous
carriers, the polymer will form not only on the surface of
the catalyst but also within the pores, eventually rupturing
the carrier. This rupture exposes fresh catalyst surfaces
which promote further polymerization. As a result catalyst
efficiency is increased. Furthermore the size of
the catalyst is kept small by the rupturing process, so that
the reaction zone remains fluidized, and does not clog up with
large masses of solid polymer. Another result of such
subdivision is a low residual catalyst content in the polymer
formed, partly because of greater dilution of the catalyst
with polymer product.
Illustrative of the claims to which no objection has been
made, and which presumably are allowable, are 1 (the
process) and 31 (the apparatus).
1. A continuous process for the production of solid
particulate polymers of olefinically unsaturated com-
pounds which comprises simultaneously:
(a) contacting, in a vertical reactor having gas
distribution plate means within and towards the base of
said reactor, a polymerization zone above said gas
distribution plate means and a gas valocity reducing
zone above said polymerization zone,
a gaseous stream containing a polymerizable olefin with
a powdery silyl chromate polymerization catalyst for
said olefin in said polymerization zone,
said polymerization zone containing a fluidized bed or
formed and forming polymer particles,
at a mass gas flow rate sufficient to maintain complete
fluidization of said bed and at a temperature below the
sintering temperature of the polymer particles,
(b) withdrawing a small portion of the fluidized bed as
discrete particles in suspension with a portion of the
gaseous stream from the reactor at a point above said
gas distributor plate means and toxards the bottom of
said polymerization zone,
(c) withdraxing the unreacted portion of said gaseous stream
from said reactor at a point above said polymerization
zone,
(d) cooling said unreacted gaseous stream to remote heat
of reaction therefrom,
(e) recycling the cooled unreacted gaseous stream through
said gas distribution plate means to the polymerization
zone at a velocity sufficient to maintain fluidization of
said bed,
(f) feeding make-up gas containing said olefin to the re-
cycled gaseous stream at a rate of feed of make-up
olefin as is equal to the rate of polymerization of said
olefin in said polymerization zone, and
(g) feeding make-up catalyst to the polymerization zone at
a rate of feed of make-up catalyst as is equal to the
rate of catalyst consumption.
31. A fluid bed reactor system in which olefin monomers may
be catalytically polymerized continuously in a fluid bed
under gas medium fluidized conditions, and comprising,
a vertical reactor having a cylindrical lower section
and an upper section having a cross section greater than
that of said lower section, said lower section being
adapted to house a polymerization zone in which the
catalyzed polymerization reaction may be conducted under
gas medium fluidized fluid bed conditions, and said
upper section being adapted to function as a velocity
reduction zone for the recovery of particles entrained in
fluidizing medium entering said upper section from said
lower section, fluidizing medium permeable distribution
plate means within and towards the base of said lower
section, said distribution plate means being adapted to
diffuse fluidizing medium up through fluidized bed in
said lower section and to support said bed thereon where
said bed is quiescent,
fluidising medium supply line means in gas communica-
sion with, and adapted to supply fluidizing medium to,
the lower section of said reactor and below said
distribution plate means,
catalyst injection means in catalyst supply communication
with, and adapted to supply particulate olefin polymeriza-
tion catalyst to, the polymerization zone in said lower
section,
polymer product recovery means in polymer product recovery
communication with, and adapted to recover polymer
product from, the base of said polymerisation zone and
above said distribution plate means,
fluidizing medium recycle line means in gas communication
with said reactor aid adapted to recover fluidizing
medium from the upper section of said reactor and to
recycle the thus recovered fluidizing medium to the lower
section of said reactor at a point below said distribution
plate means, and
heat exchange means within said recycle line means adapted
to remove heat of reaction from the recycled fluidizing
medium.
The claims filed originally were all process claims, similar
to the claim 1 quoted above, and restricted to the use of
silyl chromate catalyst. After making a preliminary amendment
in 1969, the applicant made a second amendment on June 16, 1970,
some two years after the original filing date and three years afte
the effective filing date under the International Convention.
At that time he added apparatus claims similar to the claim 31
quosed above, and further process claims similar to claims
20-30 now under rejection. Those new process claims enlarged the
scope of the protection sought by claiming the process whenever a
catalyst is used which subdivides under polymerization conditi~
The applicant subsequently restricted this slightly to exclude
certain catalysts claimed in another copending application
assigned to Union Carbide, viz Canadian Application 038,434,
now patent 876,181, G.L. Karapinka, July 20, 1971. Claim 20,
which is representative of the rejected claims, reads as follows:
A continuous process for the production of solid
particulate polymers of olefinically unsaturated com-
pounds which comprises simultaneously:
(a) contacting, in a vertical reactor having gas distribution
plate means within and towards the base of said reactor,
a polymerization zone above said gas distribution plate
means and a gas velocity reducing zone above said
polymerization zone,
a gaseous stream containing a polymerizable olefin with
a particulate polymerization catalyst for said olefin in
said polymerization zone,
said catalyst comprising a solid porous support adapted
to subdivide under the polymerization conditions, and
being other than a supported bis(cyclopentadienyl)
chromium (II) catalyst, and
said polymerization zone containing a fluidized bed of
formed and forming polymer particles,
at a mass gas flow rate sufficient to maintain complete
fluidization of said bed and at a temperature below the
sintering temperature of the polymer particles,
(b) withdrawing a small portion of the fluidized bed as discrete
particles in suspension with a portion of the gaseous
stream from the reactor at a point above said gas distri-
bution plate means and towards the bottom of said
polymerisation zone,
(c) withdrawing the unreacted portion of said gaseous stream
from said reactor at a point above said polymerization
zone,
(d) cooling said unreacted gaseous stream to remove heat of
reaction therefrom,
(e) recycling the cooled unreacted gaseous stream through
said gas distribution plate means to the polymerisation
sone at a velocity sufficient to maintain fluidization of
said bed,
(f) feeding make-up gas containing said olefin to the recycled
gaseous stream at a rate of feed of make-up olefin as is
equal to the rate of polymerization of said olefin in
said polymerization zone, and
(g) feeding make-up catalyst to the polymerization sone at
a rate of feed of make-up catalyst as is equal to the rate
of catalyst consumption.
The examiner rejected claims 20-30 on the ground that they
cover an invention which was not disclosed in nor supported
by the disclosure. He stated that they were "too broad and
indefinite." This, of course, would be contrary to Section 36
of the Pateht Act and Section 25 of the Patent Rules. It was
his contention that the only process properly supported by the
disclosure is one where silyl chromate is utilized. He phrased his
objection in the following terms:
One of the essential features of the process as disclosed
is the use of a silyl chromate catalyst. Support for
this contention is found on page 3, lines 25 to 28 where
it is stated: "It has now been found that solid
particulate olefin polymers of low, non corrosive catalyst
residue content can be obtained by continuously contacting
a gaseous stream containing a polymerizable olefin with
a powdery silyl chromate catalyst". Also on page 4,
lines 27 to 29 it is stated "This invention relates to the
continuous production of high molecular weight particulate
polymers of olefins by feeding a powdery silyl chromate
catalyst..." again on page 5, lines 23 and 24 it is stated
"The catalysts used in the practice of this invention
are silyl chromate catslysts..." On page 6, lines 4 to
6 it is stated "The silyl chromate catalysts used in the
practice of this invention are in the form of powdery free
flowing solid particles and are preferably capable of
subdivision". Furthermore all the Examples describe poly-
merization processes using silyl chromate catalysts.
There is no suggestion anywhere in the disclosure that
any catalyst other than the silyl chromate catalyst could
be need in the claimed process. Applicant's claims must
therefore be limited to silyl chromate catalyst.
Applicant's claims as originally filed were limited to
a polymerization process having the step of contacting
a gaseous stream containing a polymerizable olefin with
a powdery silyl chromate polymerization catalyst. However
by an amendment letter dated June 16, 1970 applicant in-
serted additional claims 20 to 40. New process claims
20 and 25 do not refer to silyl chromate catalyst but
instead define the catalyst as "a particulate polymerization
catalyst". In the Office Action of December 30, 1970,
the examiner objected to that expression and stated that
the only catalysts mentioned in the disclosure are silyl
chromate catalysts. In the amendment letter of March 29,
1971, applicant responded to the objection by submitting
that there is adequate support in the specification for
the use of such broad claim terminology. He noted that
the silyl chromate catalyst materials which are to be used
constitute a broad family of catalyst materials. He also
noted that various types of supports are also listed in
the disclosure. In the Office Action of April 23, 1971,
the examiner repeated the objection. In this report the
examiner agreed that the silyl chromate catalyst materials
which are disclosed constitute a broad family of catalyst
materials and that the disclosure states that the silyl
chromate catalyst may be combined with any of a variety
of supports. However the examiner pointed out that the
disclosure is limited to that silyl chromate family as an
essential element of applicant's catalyst.
By his amendment letter of October 15, 1971, applicant
amended claims 20 and 25 by inserting the statement "said
catalyst comprising a solid porous support adapted to
subdivide under the polymerization conditions". Applicant
argued in support of that amendment that the essence of
the catalyst which is to be used in the polymerization
process of the present invention is not dictated so much
by the choice of chromium compound alone, but rather by
the use of the solid porous support which is adapted to
subdivide under the polymorization conditions. Applicant
further submitted that "there is no teaching of this concept
regarding the subdividing of the catalyst in the prior art,
and therefore the applicant should be entitled to broad
protection in this regard since he is apparently the first to
claim such a concept". The examiner contends however that the
amendment to claims 20 and 25 and the supporting argument
do not overcome the objections made in the two previous
Office Actions and reiterated hereinabove. The new
statement inserted in claims 20 and 25 is functional and
merely describes a desirable characteristic of the
catalyst support. There is no indication in the disclosure
or the claims as to how the ability of the catalyst support
to subdivide is to be achieved. Reference to the dis-
closure or page 6, lines 4 to 6 which is quoted hereinbefore
indicates that the subdividable catalysts are werely a
preferred group of the silyl chromate catalysts used in
the practice of the invention.
Amended claims 20 and 25 are also objectionable in that
the statement "said catalyst comprising a solid porous
support adapted to subdivide under the polymeritation con-
ditions" introduces a further element of indefiniteness.
This statement which purports to define the catalyst, in
fact, does not define the active ingredient of the
catalyst at all. The statement describes the catalyst
support but fails to define the complete catalytic composi-
tion. The claims therefore do not comply with Section 36(2)
of the Patent Act.
Among the reasons for allowance advanced by the applicant are
the following:
1. The rejected claims are directed to the same concept
as the apparatus claims, and would grant the applicant
no greater monopoly than do the apparatus claims. Since
the apparatus claims are acceptable, claims 20-30 should
also be accepted.
2. The fact that the procedure for operating the seactor of
claiws 31-40 is disclosed in the specification only with
specific reference to the use of silyl chromate catalysts
therein should not prevent the applicant from obtaining
broader process protection relative to the choice of
catalyst. The silyl chromate catalysts, per se, and their
use as olefin polymerization catalysts, is not novel,
What is novel is the applicant's reactor and his process
for using subdividable catalysts therein, of which the
supported silyl chromate catalysts represent one family.
It is submitted that the essence of the catalyst which is
to be used in the polymerisation process of the present
invention is not dictated so much by the choice of chromium
compound alone, but rather by the use of the solid porous
support which is adapted to subdivide under the
polymerization conditions, and this concept is disclosed in
the applicant's specification, page 6, lines 12-33. This
ability for the supported catalyst to subdivide is a
unique necessity in the applicant's fluid bed process,
as contrasted to the utility of a catalyst system which
may be used in a solution or slurry system. In the latter
type of polymerization systems it is usually not
necessary for the catalysts to have this ability to subdivide,
whereas, in the applicant's fluid bed process, it is
essential that the catalyst have this property because of
the very nature of the process. As the catalyst particles
become larger and larger during the polywerization reaction
in the fluid bed process because of the accumulation of
polymer thereon they tend to sink lower and lower in the
gas stream. In order to maintain the fluidity of the fluid
bed it is necessary for the particles to subdivide so
that they can remain small enough to be maintained in
suspension. It is submitted that there is no teaching of
this concept regarding the subdividing of the catalyst
in the prior art, and therefore the applicant should be
entitled to broad protection in this regard since he
is apparently the first to claim such a concept.
It is submitted that the applicant has, in fact,
discovered a new invention relative to fluid bed poly-
merization processes wherein a specific type of solid
porous support is to be used irrespective of the other
components of the catalyst system that may be used there-
with. Once the concept of using a solid porous support
which is adapted to subdivide is made known to those in
the art, the substitution of other heavy metal compounds
or other catalyst materials for the silyl chromate com-
pounds would be obvious, and the applicant should have
broad claims relative to his contribution to the art in
this regard.
In support of those contentions the applicant relied upon
Lovell Manufacturing v Beatty (1964) 41 CPR 18 and Rodi v
Metalliflex (1961) S.C.R. 117.Concerning the objection of
indefiniteness, the applicant argued:
... the statement "said catalyst comprising a solid porous
support adapted to subdivide under the polymerization
conditions" is not indefinite with respect to the claimed
intention. The intent of the language used in this regard
is to claim, as the essence of the recited invention, the
use of a subdividable support as the support to be used
for a catalyst in a fluid bed process and not the use of
a specific active catalyst site as contended by the
Examiner. If the applicant is entitled to claim the invention
of claims 20 and 25 at all, he is entitled to claim it
in terms of the language in question. It is the applicant's
contention that, with respect to the inventive concept
of claims 20 and 25, the choice of specific catalyst sites
is irrelevant, and that the additional recitation of active
catalyst sites would add nothing by way of making more
definite the delineation of the presently claimed concept
of clams 20 and 25. The essence of the catalyst of claims
20 and 25 is the type of support to be used, not the type
of active catalyst site that may be present thereon. Thus,
while the statement in question may be broad with respect
to the catalyst definition, it is certainly not indefinite
with respect to claiming the concept which the applicant
wishes to claim, and which he believes he is entitled to claim.
The fallacy in the first argument of the applicant stems from
the fact that each claim (apart from dependent claims) must be
considered separately. In considering apparatus claims it must
be determined whether the apparatus is disclosed fully. In
considering process claims it must be determined whether the pro-
cess is disclosed fully. If the applicant means to suggest the
apparatus claims give him the same monopoly as his broad process
claims, then the process claims become redundant in affording him
the protection to which he is entitled, and their presence is con-
trary to Section 43 of the Patent Rules. In point of fact the
apparatus claims afford the applicant protection in that apparatus
no matter to what use it may subsequently be put, whether that
use be for olefin polymerization or other catalytic processes. To
that extent they provide him with a different monopoly than
the process claims. Quite possibly completely different
in his apparatus. The point at issue is not one of "greater"
and "lesser" monopolies. but of different monopolies. An
apparatus claim is patentably novel because of its own
structure or combination of parts, and not because of its
application to particular compounds.
The next consideration is whether the process is disclosed
in the same breadth as that covered by claims 20 and 25. In
the disclosure we find the following statements (underlining
added]:
(1) It has now been found that solid particulate olefin
polymess of low, non-corrosive catalyst context can be
obtained by continuously contacting a gaseous stream
containing a polymerizable olefin with a powdery silyl
chromate catalyst... (Summary of Invention, page 3).
(2) This invention relates to the continuous production
of high molecular weight particulate polymers of olefins
by feeding a powdery silyl chromate catalyst...."
(Description, p.4)
(3) the catalysts used in the practice of this invention
are silyl chromate catalysts....." (p. 5)
(4) "The silyl chromate catalysts used in the practice
of this invention are....' (p. 6)
(5) "Injecting the catalyst at a point above the distribu-
tion plate is an important feature of this invention.
The silyl chromate catalysts used in the practice of this
invention are highly active." (p.11)
(6) "The silyl chromate catalyst system of this invention
appears to yiel a product having am average particle
size of about 40 mesh.... The low residual content is
attributed to the high productivity of the silyl chromate
catalyst ....." (p.13)
(7) Each and every of the 17 examples involves the use
of a silyl chromate catalyst, and no other.
(8) The only claims filed originally, and the only claims
on file for two years, were limited to silyl chromate
catalyst.
Clearly the tenor and main thrust of the disclosure and the
original claims was directed to silyl chromate catalysts.
It would be easy to assuse that silyl chromates would be the
only catalysts useful.
The only other reference to the catalyst appears in the
abstract, which refers to "a particulate catalyst such as
a powdery silyl chromate." Since Section 27(A) (2) of
the rules specifically prohibits the use of the abstract to
interpret the scope of the invention claimed, there is no
need to consider the significance of the wording used in it.
Suffice it to point out that in Scragg v Lessona, 1964
Ex. C.R. 649 at 711 the President of the Exchequer Court
indicated that the expression "such as" must not be construed
as meaning simply "for example", but is restrictive (in this
case restricted to silyl chromate catalysts). The phrase
was also considered by the Supreme Court of Canada in Noranda
Mines v. Minerals Separation. 1950 SCR 36.
The applicant contends that he is entitled to claim obvious
modification of the specifically disclosed embodiments of
his invention, and cites both Rodi v. Metalliflex (supra) and
Lovell v. Beattey (supra) in support of that contention. Those
decisions do hold that obvious equivalents of an element
claimed in a combination would, under the circumstances that
arose, be protected by the claims. In the Rodi decision the
subject matter involved means for holding together parts of a
watch band, and with such relatively simple subject matter
it could well be obvious that other fastening means could be
utilized. In the Lovell decision the court applied the doctrine
of mechanical equivalency to an invention involving washing
machine ringers. One must, however, use caution in applying this
principle to assess whether it fits another set of circumstances.
The decision of the Supreme Court in Sandoz v Gilcross Ltd.,
formerly Jules R. Gilbert, S.C. Oct. 18, 1972, has given added
guidance on this point. As is indicated on page 10 of that
decision:
"A specification is addressed to persons skilled in
the art and, therefore, is to be construed by the
standard of what such a person would understand on
reading it."
It further held that where a specification fully describes
not only the invention but also its operation or use, it would
not invalidate a patent on here technicalities, nor did it con-
sider that Section 36(1) required it to do so.
We must decide then what a skilled chemist would take from
the disclosure given on page 6 of the application. It was pre-
viously known to polymerize olefins using the fluidized catalyst
technique. It was also known to use porous catalyst supports
(See, for example U.S. Patent 3,023,203, Feb. 29, 1962 referred
to on page 2 of the applicants disclosure). The applicant has
taught that it would be useful to carry out his process
utilizing the procedural steps specified in the claims, using
catalysts which will rupture daring the polymerisation process,
and that this rupturing could be achieved by supporting the
catalyst upon a porous carrier. He illustrated it using silyl
chromate catalysts. In our view, considering the state of the
art, it mould be obvious to skilled chemists that it would be
equally desirable with other catalysts to use his procedure and
porous carriers to produce the same result. The applicant has
not specified what such other catalysts sight be, at least in
this application, but many would be suitable. In fact, several
have subsequently been so used on porous supports which rupture
during use. Having developed this new technique, we do not
think the applicant should be restricted in the protection afford-
ed hip to its application to the specific catalyst he has
disclosed. As was held in Riddell v Patrick Harrison, (1956-1960)
Ex. C.R. 213 at 253, an inventor need not restrict his claims
to what has been "specifically described in the specification
and illustrated in the accompanying drawings," but, within the
breadth of his invention, may claim it as broadly as it would
normally be construed by persons skilled in the art. For such
reasons, we do not consider that Section 36 prohibits the grant
of claims 20-30.
The examiner's argument that the claims are indefinite
is related to his contention that claims 20 and 25 fail to
specify what catalysts are to be employed. He have con-
cluded, however, that the essence of the invention covered
by the rejected claims is not the catalyst itself, but the
particular procedure employed including the use of a porous
carrier which results in a rupturing of the catalytic material.
Under those circumstances there is no requirement upon him
to specify the particular catalyst to be used, and the indefin-
iteness to which the examiner refers is not a consideration.
The Board, then, is of the opinion that the rejection made
under Section 36 should be withdrawn.
G.A. Asher,
Chairman,
Patent Appeal Board.
I concur with the findings of the Patent Appeal Board. The
rejection made under Section 36 is to be withdrawn, and the
application returned to the Examiner for resumption of the
prosecution.
Decision accordingly
A.M. Laidlaw,
Commissioner of Patents.
Dated and signed
in Hull, Quebec this
18th day of February, 1974.
Agent for Applicant
Smart & Biggar,
Ottawa, Ontario.