T 0180/95 (Controlling of deposits/GRACE & CO.) 02-12-1996

Summary of Facts and Submissions

1. The Appellant lodged an appeal against the decision of the Examining Division on the refusal of the application No. 89 850 245.5 (publication No. 0 354 889). The decision was based on the originally filed claims, Claim 1 reading as follows:

"A method of controlling productivity disturbing microbiological deposits, e.g. slime, on paper making equipment, characterized by applying to any locus or surface of said paper making equipment which locus or surface has a tendency of causing build-ups of such microbiological deposits, a deposition-controlling amount, preferably at least about 0.1 parts per million of dilution water, of a deposition-controlling substance selected from the group consisting of cationic polymers and cationic surfactants, preferably water soluble polymers and surfactants."

2. The Examining Division held that the patent application did not meet the requirements of Article 56 EPC, having regard to the following documents:

(1) Betz, Handbook of Industrial Water Conditioning, Eigth Edition (1980), 293-301, and

(2) EP-A-0 232 015.

They considered that the closest state of the art with respect to the subject-matter of Claim 1 of the present patent application was document (1) describing the use of cationic surfactants, in particular quaternary ammonium compounds, for controlling microbiological deposits, e.g. slime, in paper mill systems. They held that in view of this state of the art the problem to be solved was to provide a process of efficiently removing the microbiological deposits from the paper making equipment and preventing their build-up, and that this problem was solved by applying the cationic surfactants to the surface of said paper making equipment instead of incorporating them into the aqueous fiber suspension. However, the application of the cationic surfactants to the places where the microbiological depositions ocurred was considered to be obvious to the skilled person. They also held that this point of view was supported by document (2) teaching the addition of deposition ("pitch") controlling substances to the paper making suspension, or to the suspension preparing or paper fabricating machinery.

3. Together with the Statement of Grounds the Appellant filed on 16 February 1995 new Claims 1 to 21. Claim 1 of this set of claims differed from that as originally filed in that the passage "selected from the group consisting of cationic polymers and cationic surfactants, preferably water soluble polymers and surfactants" was replaced by "selected from the group consisting of cationic polymers, preferably water soluble polymers".

The Appellant argued that by the new Claim 1 the claimed invention was clearly delimited from the prior art referred to in the decision of the Examining Division, since document (1) merely disclosed the use of cationic surfactants as a biocide, i.e. did not give any incentive that cationic polymers might have a similar activity. Moreover, they contended that document (2) only concerned the problem of pitch controlling, i.e. of controlling sticky water-unsoluble deposits originating from the paper making materials such as the wood, or the ink or adhesives present in recycled paper, which problem did not have any relation to the problem of controlling microbiological deposits. He concluded that in these circumstances, and in view of the examples of the present patent application showing that the convential way of treating the aqueous paper making suspension was not so efficient as that of the claimed invention, the subject-matter of present Claim 1 involved an inventive step.

4. The Appellant requested that the decision under appeal be set aside and a patent granted on the basis of Claims 1 to 21 submitted on 16 February 1995.