Buckman Laboratories (Pty) Ltd v Bromine Compounds Ltd (655/06) [2008] ZASCA 37; 2008 BIP 21 (SCA) (28 March 2008)

About SAFLII
Databases
Search
Terms of Use
RSS Feeds
South Africa: Supreme Court of Appeal
SAFLII
>>
Databases
>>
South Africa: Supreme Court of Appeal
>>
2008
>>
[2008] ZASCA 37
|

|

Buckman Laboratories (Pty) Ltd v Bromine Compounds Ltd (655/06) [2008] ZASCA 37; 2008 BIP 21 (SCA) (28 March 2008)

Links to summary

THE SUPREME COURT OF APPEAL
OF SOUTH AFRICA
Not reportable
CASE NO: 655/06
In the matter between :
BUCKMAN LABORATORIES (PTY) LTD ...
Appellant
and
BROMINE COMPOUNDS LIMITED ...
Respondent
__________________________________________________________________________
Before: STREICHER, NUGENT, HEHER JJA, HURT & SNYDERS AJJA
Heard: 25 FEBRUARY 2008
Delivered: 28 MARCH 2008
Summary: Patent – revocation in terms of s 61(1)(c) of
Patents Act 51 of 1978
– absence of inventive step.
Neutral citation: Buckman Laboratories v Bromine Compounds
(655/06)
[2008] ZASCA 37
(28 March 2008)
__________________________________________________________________________
J U D G M E N T
__________________________________________________________________________
STREICHER JA
STREICHER JA
:
[1] In an action instituted by the
respondent as the patentee of SA Patent 92/4018 in the court of the
commissioner of patents (the
court a quo) for relief in respect of
the alleged infringement of its patent by the appellant, the
commissioner of patents (Southwood
J) ordered absolution from the
instance in respect of the appellant’s counterclaim for the
revocation of the patent on the grounds
of lack of novelty and of
inventiveness and interdicted the appellant from infringing certain
claims of the patent. With the leave
of the court a quo the appellant
now appeals against the judgment.
[2] The patent is entitled ‘Process and Compositions
for the Disinfection of Waters’. Claim 1 of the patent reads as
follows:
‘
A process for killing microorganisms and
controlling biofouling in high chlorine demand circulating waters,
which comprises mixing
two components, one of which is an oxidant in
the form of a chlorine precursor in solution and the other an
ammonium salt in solution
thereby forming a biocidal mixture, and
adding the biocidal mixture immediately to the high chlorine demand
aqueous system to be
treated.’
The claim can be divided into the following integers:
A process for killing micro-organisms and controlling
biofouling in high chlorine demand circulating waters;
Which comprises mixing two components;
One of which is an oxidant in the form of a chlorine
precursor in solution;
And the other an ammonium salt in solution;
Thereby forming a biocidal mixture;
And adding the biocidal mixture immediately to the high
chlorine demand aqueous system to be treated.’
Claims 2 to 13 are dependent on claim 1. Claim 14 is a
separate independent claim but has the same scope as claim 1 with the
exception
that the process is limited to the treatment of circulating
waters of paper industry systems. Claims 15 to 26 are dependent on
claim
14. The priority date of the patent is 3 June 1991.
[3] It is common cause between the parties that, in the
event of the respondent’s patent being valid, the appellant is
infringing
the patent in that the appellant, at a number of paper
mill plants, is using a process for disinfecting water in which the
features
of claims 1, 2, 6, 10, 13, 14, 15, 19, 23 and 26 of the
patent are present. The appellant, however, in its counterclaim,
claims that
the patent is invalid for the reason that the invention
claimed in these claims was not new and did not involve an inventive
step.
As stated above the court a quo dismissed the appellant’s
counterclaim. In the light of the conclusion to which I have come in
respect of the question whether claims 1 and 14 involve an inventive
step I shall assume without deciding that the court a quo’s
finding
in respect of novelty is correct and deal only with the question of
obviousness in respect of these two claims.
[4] In terms of
s 61(1)(c)
of the
Patents Act 57 of
1978
a patent may be revoked on the ground that the invention is not
patentable under
s 25.
Under
s 25(1)
a patent may not be
granted to an invention which does not involve an inventive step. In
terms of
s 25(10)
an invention shall be deemed to involve an
inventive step if it is not obvious to a person skilled in the art,
having regard to any
matter which forms, immediately before the
priority date of the invention, part of the state of the art by
virtue of
s 25(6).
The state of the art, in terms of that
section, ‘shall comprise all matter (whether a product, a process,
information about either,
or anything else) which has been made
available to the public (whether in the Republic or elsewhere) by
written or oral description,
by use or in any other way.’
[5] The court a quo described the relevant art as the
‘disinfection of high chlorine demand circulating waters’. In my
view this
description of the relevant art is too restrictive.
Professor Cloete, the head of the Department of Microbiology and
Plant Pathology
at the University of Pretoria, testified that the
title of the patent namely ‘Process and Compositions for the
Disinfection of
Waters’ was an accurate description of the art to
which the patent relates and his evidence in this regard was never
challenged.
The skilled addressee, according to the court a quo, is a
person with a tertiary qualification in microbiology and chemistry.
Neither
the appellant nor the respondent took issue with this
finding.
[6] Regarding the state of the art at
the relevant time the appellant relied on various articles, amongst
others: Hirschkind,
Chloramine,
Its Preparation, Properties, and Uses
Western
Construction News, dated 25 October 1930; Enslow,
Ammonia-Chlorine
Reactions and Chloramine Production – In Water and Sewage Treatment
Contract Record and Engineering
Review, dated 11 March 1931; Schirtzinger,
Chlorine
compounds for microbiological control
Paper
Mill News, dated 29 July 1963; and Beck and others,
Preformed
Monochloramine Used as a Post-Disinfectant in Drinking Water
Treatment at Sjælsø
Water
Works
Aqua (1)
1986. The appellant also relied on a number of patent specifications,
amongst others: USA Patent No 1,378,644 titled
Process
of Sterilizing
,
dated 17 May 1921 (‘the Baker patent’); and GB Patent No 1600289
titled ‘
Sterilisation
of Water for Nutrient Film Systems
’
dated
26 August 1977 (‘the Wilson patent’). The respondent did not
tender any evidence while the appellant called Professors Cloete
and
Pretorius as expert witnesses. Prof Pretorius obtained a DSc degree
in the field of microbiology from the University of Pretoria
and an
MSSan Engineering degree from the University of California. Before
his retirement he held the chair of Water Utilisation in
the
Department of Chemical Engineering at the University of Pretoria. In
the light of these publications, the specification and the
evidence,
the state of the art, in so far as it is relevant, can be summarised
as follows.
[7] Biological fouling of circulating water is a known
and well documented problem. It involves the growth of unwanted
micro-organisms
in water systems. The unwanted micro-organisms
include bacteria, fungi, protozoa and algae. Such biological growth,
according to
the specification, can foul pipelines, accelerate
corrosion, attack wood, decrease heat transfer, plug filters, cause
imperfections
in paper sheets, decompose sizing mixtures, and cause
many other process interferences. The micro-organisms can be killed
and the
water can thus be disinfected by the use of oxidising
biocides. Chlorine is such an oxidising biocide and is widely used in
circulating
water. It will kill or chemically incinerate the
micro-organisms through an oxidation reduction reaction.
[8] When chlorine is added to water the chlorine reacts
with substances in the water and is thereby reduced or converted to
inert
or less active forms of chlorine. Breakpoint is reached when a
complete reaction has taken place with all chlorine-reactable
materials.
The quantity of chlorine required to reach this point ie
the quantity of chlorine that is reduced or converted to inert or
less active
forms of chlorine by substances in the water over a given
period is known as the chlorine demand of the water. Such demand is
expressed
as the difference between the amount of chlorine applied
and the amount of free chlorine remaining at the end of the contact
period
eg 1.8 parts per million (‘ppm’) out of 2.0 ppm chlorine
after 60 minutes.
[9] When a chlorine precursor in solution, eg
hypochlorous acid, is mixed with an ammonium salt in solution, a
chloramine is formed.
Like chlorine, chloramine is an oxidising
biocide ie it will kill micro-organisms. Depending on the pH level of
the water three types
of chloramine compounds can be formed namely
monochloramine, dichloramine and nitrogen trichloride. If the pH is
below 4.5 the dominant
compound would be nitrogen trichloride, if it
is between 4.5 and 7.5 the dominant compound would be a dichloramine
and if it is above
7.5 it would be monochloramine. Chloramine is an
effective sterilizing agent and has the advantage that it remains
unabsorbed for
a much longer period than free chlorine.
[10] The sterilizing effect of chloramines has been
known since about 1910 and by the priority date of the patent a large
amount of
material had been written on the effectiveness of
chloramine compounds in water. In 1930 Hirschkind dealing with the
preparation,
properties and uses of chloramine wrote that the low
oxidation potential of chloramines causes them to persist for a
longer time
than chlorine alone and makes their application possible
in cases where chlorine alone would be immediately used up by
oxidation,
as for instance in industrial slimes. He stated that large
dosages of chlorine, which are sometimes resorted to, to take care of
heavy bacterial loads or to kill algae, and which may leave
disagreeable odours and tastes, can be subsituted, without these
adverse
side-effects, by chloramines alone. For most commercial uses,
he said, it may be found advantageous to prepare the chloramine first
and add it as such to the point of application. Dealing with the
production of chloramine by the reaction of chlorine with ammonia
he
concluded that the pH level of the solution plays an important role
in stabilizing chloramine solutions and that if acid conditions
are
avoided the chloramine decomposition is slow.
[11] In
1931
Enslow in his article on ammonia-chlorine reactions and chloramine
production in water and sewage treatment, stated that it may
in
certain instances prove to be desirable to employ a ready prepared
chloramine solution in preference to the application of ammonia
and
chlorine separately. He then described how monochloramine could be
produced by adding an ammonia salt in solution to hypochlorous
acid,
a chlorine precursor in solution.
[12] In the specification of the Baker patent (1921) it
is stated that the inventor had found that in certain liquids such as
sewage
ie high chlorine demand water, or other chlorine consuming
liquids, sterilization may be effected with a lesser proportion of
nitrogen
trichloride than would be required of chlorine. The
specification describes how nitrogen trichloride, a chloramine, can
be produced
by mixing hypochlorous acid with an ammonium compound
such as ammonium sulphate, an ammonium salt, in solution. Claim 2 of
the Baker
patent requires the solution so produced to be utilised
‘immediately as produced as a sterilizing agent’. The respondent,
in
oral argument before us, submitted that regard could not be had to
the Baker patent in that the appellant was not relying thereon.
However, the Baker patent is mentioned in the appellant’s
counterclaim as one of the prior art documents relied upon,
respondent’s
counsel dealt with the Baker patent in his
cross-examination of Prof Cloete, and, in their heads of argument,
respondents’ counsel
referred to the Baker patent and stated: ‘It
does not teach the preforming of an unstable biocide and adding that
biocide immediately
to the water to be treated.’
[13] In 1963 Schirtzinger, writing about slime control
in white water systems in the pulp and paper industry ie high
chlorine demand
circulating waters, said that current water treatment
practice used free chlorine rather than combined forms of chlorine
for microbiological
control but that in white water systems
chloramines were more effective. According to him, the use of
chloramines will produce effective
slime control at exceptionally low
cost in paper white water systems. Slime consists of a gelatinous
mass caused by bacteria, in
which fungi and algae accumulate,
propagate and become highly objectionable. Schirtzinger stated
furthermore, and Prof Cloete agreed,
that there is no resistance of
any particular strain of microorganism to chlorine compounds and that
the combination of chloramines
concentration and contact time would
destroy slime-forming organisms.
[14] Prof Cloete testified that it
would be ‘a natural step to take an excellent disinfectant
technology [from waste water applications]
and move it into other
applications [for instance paper mills, cooling towers and the
like]’. Prof Pretorius, referring to chloramines,
testified that
‘the disinfectant that is supplied is supplied to . . . virtually
the whole spectrum of water that we are using,
whether it is waste
water or drinking water or whatever it be, it is a universal oxidant
or a universal disinfectant’.
[15] The Wilson patent relates to the
sterilisation of water in a system called a nutrient film system in
which plants are grown with
their roots immersed in a flowing film of
liquid containing plant nutrients. In the specification the system is
described as follows:
‘Typically, a shallow waterproof trough is
formed and a film of aqueous nutrient solution flows through the
trough, is collected,
e.g. in a sump tank, and recycled, e.g. to a
header tank, from whence it is fed back to the trough. During the
cycle, water and nutrients
are taken up by the plant and these
require replacement before the nutrient solution is recycled.’ The
nutrients consist of a water
soluble fertilizer composition.
According to the specification chlorine can be used as the
sterilizing agent and in this regard it
is said that chloramines
provide a particularly preferred form of available chlorine since
they have a slower action than uncombined
available chlorine. The
chloramine is conveniently formed
in
situ
in the water
or in a separate vessel from which it is dosed at the desired rate
into the water. Where an aqueous solution of the pathogenicide
is
being dosed this may be done by any suitable means eg by feeding it
to the throat of a venturi in the water feed line or into
the
circulating nutrient solution in the nutrient film system. Claim 1 of
the Wilson patent reads as follows:
‘
1.
A
process for treating water fed to or circulating in a nutrient film
system which comprises incorporating a plant physiologically
acceptable amount of a pathogenicide into the water.’
In terms of claim 5 the pathogenicide is a chloramine,
in terms of claim 10 a preformed pathogenicide may be added and in
terms of
claim 12 a preformed pathogenicide may be fed to the water
in association with fertilizer ingredients.
[16] Professor Pretorius testified that a nutrient film
system such as the one discussed in the Wilson patent, will have a
high chlorine
demand. According to his evidence, anybody that is
knowledgeable about these systems knows that any plant growing in
water is liberating
organic material from the root phase which
accumulates in the water as humus and causes a high chlorine demand
apart from the nitrogen
introduced as a nutrient as well as any
microorganisms or pathogens that may develop. This evidence was never
challenged in cross-examination.
Counsel for the respondent put to
him that ‘the document does not describe how to get to the
arithmetic . . . to determine if it
is high or low chlorine demand’
and Prof Pretorius agreed. He also agreed that in the case of the
mixing of a chlorine precursor
with fertilizer containing an ammonium
salt in a separate chamber before addition thereof to the circulating
water, the chlorine
demand is created by the fertilizer. However, his
evidence that the system would have a high chlorine demand for the
other reasons
given by him, was left unassailed.
[17] Beck, writing in 1986, in dealing with the use of
preformed monochloramine as a post-disinfectant in drinking water
treatment,
described how a stable monochloramine could be produced by
the use of ammonium sulphate and hypochlorite solutions.
[18] It follows that as at the priority date of the
patent it was well documented that a biocidal mixture (chloramine)
could be formed
by mixing two components consisting of an oxidant in
the form of a chlorine precursor in solution and an ammonium salt in
solution
and that such biocide could be used to kill microorganisms
and to control biofouling in high chlorine demand circulating waters
by
adding the biocidal mixture to the high chlorine demand aqueous
system to be treated. This is the process described in claim 1 and
14
with only one exception and that is that according to these claims
the biocidal mixture must be added immediately. In the
cross-examination
of the witnesses it was repeatedly stressed by the
respondent’s counsel that, in the processes being referred to, it
was not said
that the chloramine had to be added immediately after
its formation. However, in the case of the Baker patent immediate
addition
of the chloramine is required because of the volatitilty of
nitrogen trichloride.
[19] Professor Cloete, referring to the claims of the
patent, testified that he did not know what the inventive step was as
all that
has been said was known. Professor Pretorius’ evidence was
to the same effect. In regard to the requirement that the biocide be
added immediately Prof Cloete testified that he did not ‘think that
there would be any disadvantage of adding it immediately’
and that
‘when you produce any compound and particularly where you are
dealing with oxidising biocides, which are generally less
stable than
non-oxidising biocides, you would actually want to get them into your
water system as soon as possible. . . .the maximum
efficacy you will
actually get just after you have actually made the product and I
would argue that it . . . makes common sense’.
[20] Notwithstanding the fact that the inventor, Dr
Ayala Barak, was available to testify and that a summary of the
expert evidence
that she would give had been delivered, the
respondent did not call her as a witness. The court a quo
nevertheless had regard to
her summary to determine what the inventor
claimed the inventive step to be and concluded: ‘Thus, according to
the summary, the
process of the invention, contrary to the
conventional wisdom of the time, deliberately aims to produce an
unstable biocide. It is
because of that instability that the biocide
mixture is added to the aqueous system to be treated immediately.’
[21] Dealing with the contention that the process of the
invention deliberately aimed to produce an unstable biocide the court
a quo
said that if that was the aim of the invention ‘this seems to
be essential to an understanding of the invention and required
emphasis
to show why the biocide is added immediately to the high
chlorine demand aqueous system. The absence of any reference to the
biocide
being unstable is indicative of this not being the case. The
evidence relating to the examples in the 1995 patent seems to put the
matter beyond doubt.’
[22] The reference to the 1995 patent is a reference to
South African Patent 95/8275 which is also in respect of a method of
treating
liquids to inhibit the growth of living organisms and in
respect of which the inventor is also stated to be Ayala Barak.
According
to the specification the decomposition rates of various
biocidal mixtures were monitored and in the case of a concentrated
solution
of ammonium sulphate (an ammonium salt) and sodium
hypochlorite (a chlorine precursor) the rate of decomposition of the
active biocidal
ingredient (a chloramine) was found to be relatively
stable for a period of two and a half hours.
[23] In regard to counsel for the respondent’s
submission that ‘adding the biocide formed immediately to the
aqueous system to
be treated was at least part of the inventive step
of the patent’, the court a quo held:
‘
Chlorine (chlorination) and chloramines
(chloramination) had been used for the disinfection of water and
water systems for about 80
years when the patent was granted.
Notwithstanding extensive use in paper mill systems which obviously
include high chlorine demand
circulating waters, the literature
dealing with the processes used does not suggest the combination of
the integers of the plaintiff’s
invention to deal with the
microorganisms and other matter found in the water and the
circulating waters. The evidence does not suggest
that any other
similar process was conceived to deal with the problems experienced
in the paper mills. Whatever the position with
regard to the
instability of the biocide produced it seems clear that the invention
works. In these circumstances it seems that the
selection of the two
components, the mixing of these components (both in solution) outside
the aqueous system to be treated and the
immediate addition of the
biocide constitutes the scintilla of the invention required.’
[24] Before us counsel for the respondent submitted that
the combination of all the integers of the invention constituted the
inventive
step. The conventional wisdom at the priority date, so he
submitted, taught the production of a stable biocide that has a
lasting
disinfecting effect while the patent on the other hand, aims
at creating an unstable biocide that is highly efficient when added
immediately.
[25] On the evidence it is clear that chloramines of
varying stability can be produced. The patent makes no mention of the
stability
of the biocide. Stability of the biocide is therefore not a
feature of the patent at all. At the priority date it had been stated
in various publications that chloramines could be used to sterilize
high chlorine demand circulating waters, including paper industry
systems and that preformed chloramines could be used to treat high
chlorine demand water such as sewage and also high chlorine demand
circulating waters. It follows that ignoring the Baker patent as
respondent’s counsel urged us to do, the inventive step could
only
have been the immediate addition thereof. However, according to
Cloete, where you are dealing with oxidising biocides which
are
generally less stable than non-oxidising biocides and whose
efficiency would be at its maximum just after you have made them
it
makes common sense to add them immediately. No reason was suggested
why anybody would have thought that one should not add the
preformed
chloramine immediately. In these circumstances it is in my view
obvious and would, as at the priority date, have been obvious
to a
person skilled in the relevant art, that preformed chloramine could
be added immediately or, depending on its stability, later.
[26] The fact that the process described in the patent,
on the priority date, had not been used in paper mill systems
notwithstanding
extensive use of chloramines in such systems and
notwithstanding the use of chloramines for the disinfection of water
for about 80
years does not assist the respondent. It had been stated
that it could be done and that statement proved to be correct. The
fact
that the process works, therefore, does not assist the
respondent either.
[27] It follows that the invention embodied in claims 1
and 14 lacked an inventive step and that the patent should for that
reason
not have been granted. We were asked to also deal with the
claims dependent on claims 1 and 14 but that may be an academic
exercise
on which we do not wish to embark.
[28] The respondent asked and the appellant did not
object that, in the event of it being held that the patent is
invalid, it be afforded
an opportunity to apply for the amendment of
the patent.
[29] The following order is made:
a) The appeal is upheld with costs including the costs
of two counsel.
b) The order made by the court a quo is replaced with
the following order:
(i) The plaintiff’s action is
dismissed with costs including the costs of two counsel.
(ii) The defendant’s counterclaim
for the revocation of SA Patent 92/4018 is granted and, subject to
what is ordered in subparagraph
(iii) below, the patent is revoked.
(iii) The revocation order granted in
subparagraph (ii) is provisional. It will become fully operative in
respect of the patent concerned,
if the patentee does not within one
month file notice of an application to amend such patent, or if
having filed such application,
the patentee withdraws it. If an
application as aforesaid is made and not withdrawn, it shall be
decided at the hearing of such application
whether or not the
revocation order is to be put into operation.
(iv) The plaintiff is ordered to pay
the defendant’s costs in respect of the counterclaim including the
costs of two counsel.
__________________
P E STREICHER
JUDGE OF APPEAL
CONCUR
:
NUGENT JA)
HEHER JA)
HURT AJA)
SNYDERS AJA)