DOI: 10.1595/147106708X362735

Platinum Group Metals Patent Analysis and Mapping A REVIEW OF PATENTING TRENDS AND IDENTIFICATION OF EMERGING TECHNOLOGIES By Richard Seymour Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.; E-mail: [email protected]

The patent literature contains a wealth of detailed information about existing and new uses for the platinum group metals (pgms). While excellent searching tools have existed for many years for identifying patents relating to specific topics, it is only relatively recently that it has been feasible to map the complete archive of patent literature to identify important trends relating to potential new applications. This paper summarises the results of such an exercise for the pgms carried out in early 2008 and shows that one such ‘hot spot’ relates to organic light emitting diodes (OLEDs).

Previous articles in this Journal have described the importance of patents as a key source of technical and commercial intelligence (1, 2). The use of patent mapping to visualise large sets of patent data and to identify trends contained within that data has also been demonstrated (2). The present paper further develops these themes by examining the patent literature on pgms published since 1983, in particular that on the minor metals iridium and ruthenium.

Searching – What and Where? I will begin by thinking about search strategy. In this case, the initial objective is to create a large set of patents relating to the pgms, which will later be analysed and refined. The choice of keywords is therefore straightforward: platinum, palladium, rhodium, iridium, osmium and ruthenium. In the patent literature it is unlikely that the names of these metals would be used in other contexts. However, this might be a difficult problem if we were searching the news or business press, where the names of the pgms are associated with many brand names – for example there would probably be many hits on topics such as platinum credit cards or iridium satellite communication systems, and strategies for removing such material would need to be found. Perhaps a more important question to ask is which patent collections to use to search for these words? The software package used at the Johnson

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Matthey Technology Centre is Aureka® (a product available from Thomson Reuters) (3), which includes patent data sets from the Patent Cooperation Treaty (PCT) and European Patent offices, plus a range of national patent collections including those of the U.S.A., Japan, the U.K., France and Germany. With the exception of Japan, these collections contain full-text patent documents, available either as PDF or HTML files. In the case of Japanese patents, a text version of the English-language title, abstract and other front page details is available, together with a PDF file of the full specification in Japanese. It must be borne in mind that using the French and German collections would require us to search in French or German respectively, and of course the results obtained would also be in French or German. The patent collections of other countries, for example China and India, are not currently available in Aureka. However at this stage we are looking for the big picture. The detail can follow later if necessary, for example by adding Chinese patent documents retrieved from other patent databases. We also need to think about where in the patent document we might wish to search for information on pgms. This is an important question and to understand the various possibilities and their implications we first need to think about the structure of a typical patent:

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– Title: often deliberately rather vague and nonspecific. – Abstract: a short summary of the invention, in perhaps 100 to 200 words. – Claims: the claims of a patent govern its legal effect, that is, the areas of technology that are to be monopolised. Generally it can be said that a feature is not protected unless that feature is claimed or covered by the general language in the claims. So these are key – get the claims wrong and your invention may be seriously compromised. Then, depending on the particular country, there may also be sections on: – Background: provides details on the context of the invention, current technology, and why existing solutions may be inadequate. – Description: a detailed description of the invention and possible variants thereof. – Examples: worked examples, covering aspects such as how the invention is made. Scientists sometimes wrongly concentrate on the examples just as they would read the experimental sections of scientific papers. Now let us suppose we are searching for patents in which a new pgm chemical or material is disclosed, or in which the use of a pgm is a key part of the invention. In this case restricting the search to terms in the title or abstract, and possibly also the claims, will be adequate. Clearly if the word ‘platinum’ appears in any of these sections then it is likely to be a very important part of the invention. But what about the case when the name of the pgm appears somewhere in the rest of the patent, but not in the title, abstract or claims? Can these patents safely be ignored? An example of such patents might be the use of a standard palladium on carbon hydrogenation catalyst in a multi-stage organic synthesis route. The novelty is in the endproduct, not the catalyst used, and therefore the term ‘palladium’ is unlikely to occur in the title, abstract or claims. However it may well come up in the examples. While we can probably ignore such patents for the purpose of identifying key new application areas, important information may nevertheless be obtained from them. For example, they may provide valuable intelligence on sales

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opportunities for suppliers of catalysts, the customer being the owner of the patent. Table I illustrates the wide variation in the number of retrieved patents obtained according to where in the patent the search is performed. The table clearly shows that choosing which part of the patent document to search is critical. If we search in the patent title, abstract and claims then we retrieve over five times as many patents as exactly the same search restricted to just title and abstract. If we search in the full text of the patent then we retrieve five times as many again. Table I

Searches on the Term ‘Platinum’ Conducted in the U.S. Granted Patent Collection, for Patents Published between 1st January 2001 and 31st December 2007 Criteria

Number of ‘hits’

‘Platinum’ in the patent title or abstract

1611

‘Platinum’ in the patent title, abstract or claims

8878

‘Platinum’ in the patent full-text

44,541

‘Platinum’ in the patent full-text but not title, abstract or claims

35,663

Table II shows the top fifteen assignees for each set of results in Table I. It shows that we might expect to obtain quite different results for the various searches, even though the keyword is the same in each case. Apart from Micron Technology Inc, which heads up each list, there are some very significant differences. Engelhard (now BASF Catalysts) comes in at number five in the ‘title or abstract’ search but does not appear in the ‘title, abstract or claims’ or full-text searches. On the other hand, the Semiconductor Energy Laboratory, while it does not appear in the ‘title or abstract’ search, and only reaches number twelve in the ‘title, abstract or claims’ search, comes in at number two in the full-text search. Pfizer is another good example. Like Semiconductor Energy Laboratory, this company

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Table II

Search Results by Top Fifteen Assignees for Patents in the U.S. Granted Patent Collection, Published between 1st January 2001 and 31st December 2007 Rank

‘Platinum’ in patent title or abstract (1611 patents)

‘Platinum’ in patent title, abstract or claims (8878 patents)

‘Platinum’ in patent full-text but not title, abstract or claims (35,663 patents)

1

Micron Technology Inc

Micron Technology Inc

Micron Technology Inc

2

General Electric

General Electric

Semiconductor Energy Laboratory

3

Shin-Etsu Chemical Co

IBM

Fuji Photo Film Co Ltd

4

UOP LLC

Samsung Electronics Co Ltd

Eastman Kodak

Advanced Micro Devices Inc

Canon KK

1

5

Engelhard Corporation

6

Dow Corning

Matsushita Electric Industrial Co Ltd

Matsushita Electric Industrial Co Ltd

7

Matsushita Electric Industrial Co Ltd

Shin-Etsu Chemical Co

General Electric

8

Texas Instruments Inc

Intel Corp

3M Innovative Properties Co

9

Dow Corning Toray Silicone

Infineon Technologies AG

IBM

10

IBM

Hitachi Ltd

NGK Insulators Ltd

11

Advanced Cardiovascular Systems

Institut Francais du Petrole

Seiko Epson

12

Samsung Electronics Co Ltd

Semiconductor Energy Laboratory

Medtronic Inc

13

Honeywell International Inc

UOP LLC

Pfizer

14

Infineon Technologies AG

Texas Instruments Inc

Sony Corp

15

BASF

Hewlett-Packard Development Co

Hitachi Ltd

1

Now BASF Catalysts

only appears in the top assignees from the full-text search. One would expect Pfizer’s main interest in platinum to be as a user of catalysts in pharmaceutical manufacturing, rather than as a developer of new pgm-based technologies. Manual inspection of selected Pfizer patents confirms this to be the case.

The Results List and Initial Analysis For the remainder of this paper we will be considering the results of searches based on the names of the pgms in the patent title or abstract. We have undertaken the search in the U.S., European and PCT patent collections, for patent applications or granted patents published in the period from 1st January 1983 to 31st December 2007. The search results have then been ‘deduplicated’ to exclude

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patent family members filed in different geographical regions, to leave one patent per invention. The final document list contains just over 13,540 patents. Figure 1 shows a basic breakdown of these patents by metal and by five-year timeslices. Overall growth in pgm patents in the period from 1983 to 2007 is about 6% per annum. In the last seven years, this growth rate has been nearly 13%. However, growth in the number of patents by individual metal is not completely uniform. There has been somewhat higher growth for platinum, ruthenium and iridium patents, and slightly lower growth for palladium and rhodium, as shown in Table III. A comparison between the pgm patent picture and that for a number of other metals (gold, silver,

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Number of patents published

7000 6000 Osmium

5000

Iridium

4000

Fig. 1 PGM patents by metal – number published in five-year time periods

Ruthenium

3000

Rhodium

2000

Palladium

1000

Platinum

0 20 7

00

–2

03 2

00

–2

7

2

99

–1

98

93

19

19 99

–1

7

98

–1

88

83

19

19

Time period

nickel and cobalt) is shown in Figure 2. The number of patents on all these metals has increased. However the rate of increase for pgms and gold is considerably higher than that for nickel, cobalt and silver. This is illustrated in Table IV by looking at the earliest (1983–1987) and latest (2003–2007) time periods. Figure 3 shows the importance of these metals in selected technology areas. The analysis was based on selected International Patent Classification (IPC) codes (4).

Patent Mapping The Aureka ThemeScapeTM tool (3) was used to create a visualisation of the pgm document list described above. The results are shown in Figure 4. The resulting map looks like a mountainous island

surrounded by sea. The visualisation is helpful because ThemeScape groups together similar documents and labels these groups according to frequently used key terms found within those groups. The more documents contained within each group, the higher the ‘mountain’ appears. The automatic labelling sometimes produces meaningful headings (e.g. silicone, rubber, polysiloxane), but sometimes these are less obviously meaningful (compounds, preparation, reaction). Where necessary these can be edited following an inspection of documents contained within the groups. The grey dots represent sample documents – in this set of 13,540 documents only a small proportion are shown in this view, but more (or all) documents will be shown when specific areas are magnified. Clicking on specific dots will display the

Table III

PGM Patents by Metal: Number and Proportion of Patents Containing Specific PGMs Published in Early (1983–1987) and Recent (2003–2007) Time Periods Metal

Patents containing specific pgms vs. total pgm patents, 1983–1987

Patents containing specific pgms vs. total pgm patents, 2003–2007

Number

Number

Proportion, %

Proportion, %

Platinum Palladium Rhodium Ruthenium Iridium Osmium

840 659 408 349 184 56

46 36 22 19 10 3

2265 1452 689 1024 613 189

52 33 16 23 14 4

1

18331

–

43921

–

Total 1

This is not the arithmetic sum as more than one pgm can appear in any given document

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Number of patents published

20000 18000 16000 14000 12000 10000 8000 6000 4000 2000 0

Cobalt Nickel Silver Gold

Fig. 2 Comparison of pgms with selected other metals – number of patents published in five-year time periods

PGM

20 03 7

00

2

7

00

–2

–2

99

2

7

99

–1

98

93

19

19

–1

98

–1

88

83

19

19

Time period

Heterogeneous catalysts

Technology area

Semiconductors or Electronics PGM

Homogeneous catalysts

Gold Fuel cells and batteries

Silver Nickel

Coated products

Cobalt

Alloys Medical 0

500

1000 1500 Number of patents

2000

Fig. 3 Relative importance of various metals in selected technology areas, by IPC code, for the time period between 1st January 2003 and 31st December 2007 Table IV

PGM Patents vs. Other Metals: Number and Proportion of Patents Containing Specific Metals Published in Early (1983–1987) and Recent (2003–2007) Time Periods Metal

PGMs Gold Silver Nickel Cobalt 1

Total

Patents containing specific metals vs. total metal patents, 1983–1987

Patents containing specific metals vs. total metal patents, 2003–2007

Number

Number

Proportion, %

Proportion, %

1833 646 2009 2200 1279

28 10 31 34 20

4392 2152 4062 4626 2441

31 15 28 32 17

65361

–

14,2931

–

1

This is not the arithmetic sum as more than one pgm can appear in any given document

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Fig. 4 PGM patent map covering granted patents or patent applications published between 1st January 1983 and 31st December 2007

original document. The contour lines enclosing particular areas can be used to select groups of documents for inspection or further analysis. In Figure 5, we have further processed the basic map shown in Figure 4 in two ways. Firstly, to create a timeslice covering documents published only in the period January 2003 to December 2007; secondly, to show patents on platinum as red dots and patents on palladium as green dots. Where specific documents cover both platinum and palladium, these are shown as white dots. The reason for this exercise is to show the relative importance of particular metals in specific technology areas. For example, the ‘silicone, rubber, organopolysiloxane’ and ‘fuel cell, fuel, electrode’ areas are dominated by red dots, indicating that platinum is the preferred metal in these applications. The ‘plating, deposited, substrate’ region is dominated by green dots, confirming the importance of palladium in electronic applications.

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The ‘exhaust, engine, oxide’ area contains many red, green and white dots, indicating that both metals may be used in emission control applications. Figure 6 is a similar image showing the minor metals rhodium, ruthenium, iridium and osmium. Of particular interest here are the two boxed areas, the first just left of centre, the second centre right. These contain a cluster of mainly light blue dots (ruthenium) and dark blue dots (iridium), respectively. Comparison of the number of dots with the same areas in Figure 7, covering the 1993 to 1997 timeslice, shows a marked increase in the numbers of iridium and ruthenium patents published in 2003–2007. These are examples of emerging technologies. Magnification of one of these areas (see Figure 8) shows that this area includes many patents on organic light emitting diodes (OLEDs), which is an important potential new application for iridium-based fluorescent or phosphorescent dopants. OLEDs (see also

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Fig. 5 PGM patent map timeslice 2003–2007, showing occurrences of platinum patents (red dots), palladium patents (green dots), and patents covering both platinum and palladium (white dots)

References (5, 6)) are solid-state devices composed of thin films of organic molecules that create light with the application of an electric current. Compared with conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs), OLEDs provide brighter, crisper displays which require less power. It has been discovered that in some iridium complexes, strong spin-orbit coupling leads to singlet-triplet mixing, ideal for highly efficient electrophosphorescence required for future OLEDs. Companies with pgm patents in the OLED area currently include DuPont (U.S.A.), Samsung (Korea), LG Electronics (Korea), Idemitsu Kosan (Japan) and Konica Minolta (Japan). Further analysis of the map shows that ruthenium-based interconnects and electrodes, iridium-based capacitor materials, new magnetic materials containing iridium or ruthenium, ruthenium-based metathesis catalysts (for example

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Grubbs’ catalyst) and the application of ruthenium in silane production are other emerging technology areas.

The Non-Patent Literature While patents are an extremely important source of technical and commercial intelligence, there is also a huge amount of non-patent literature covering the pgms. This is illustrated in Figure 9, which compares the size of the patent literature on ruthenium with that of the non-patent scientific literature on the uses of this metal in chemistry-related areas. The top ten uses for ruthenium in the non-patent literature, based on controlled index terms used in the Chemical Abstracts database, are shown in Table V. Specialised software tools such as STN® AnaVistTM (7) are now available to assist with the analysis of non-patent (as well as patent) literature, similar to that described above for the patent data.

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Fig. 6 PGM patent map timeslice 2003–2007, showing occurrences of rhodium patents (yellow dots), iridium patents (dark blue dots), ruthenium patents (light blue dots), osmium patents (purple dots), and patents covering two or more minor metals (white dots) Table V

Top Ten Uses for Ruthenium from the Non-Patent Chemical Literature, 2003–2007 Publication index term Fuel cells Oxidation catalysts Hydrogenation catalysts Nanoparticles Oxidation, electrochemical Carbon black, uses Fluoropolymers, uses Magnetisation Spin valves Vapour deposition process

Proportion of total, 2003–2007, % 11.2 10.7 9.4 5.2 4.4 4.1 3.7 3.7 3.7 3.4

Conclusions The patent literature is an extensive and detailed source of information on existing and potential new applications for the pgms. At the

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time of writing, there are in the region of 13,540 inventions, covering the period from January 1983, in which the use of one or more pgms is a key part of the inventive step. There are many others in which pgms may be used, for example as part of a complex organic synthesis route. Growth of this literature is expected to continue to increase at a rate slightly higher than that of certain base metals. Patent mapping tools can be used to identify key areas of development and ‘hot spots’ of activity which may lead to future volume applications. ‘Hot spot’ areas for the minor metals ruthenium and iridium currently include iridium in organic light emitting diodes (OLEDs), ruthenium-based interconnects and electrodes, iridium-based capacitor materials, new magnetic materials containing iridium and/or ruthenium, and the application of ruthenium in silane production.

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Fig. 7 PGM patent map timeslice 1993–1997, showing occurrences of rhodium patents (yellow dots), iridium patents (dark blue dots), ruthenium patents (light blue dots), osmium patents (purple dots), and patents covering two or more minor metals (white dots) Fig. 8 Magnified view of centre-right box shown in Figure 6 for timeslice 2003–2007, showing occurrences of iridium patents (dark blue dots), ruthenium patents (light blue dots), and patents covering two or more minor metals (white dots)

Iridium OLED Electroluminescent

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Number of publications

3500 3000 2500

Patents

2000 1500

Fig. 9 Trends in the non-patent literature – number of publications in patent and non-patent literature for ruthenium

Non-patents (uses)

1000 500 0 20 03 –2 7

2

00

00

7

2

99

–2

–1

98

93

19

19

7

99

98

–1

–1

88

83

19

19

Time period

References 1 2 3 4

I. Wishart, Platinum Metals Rev., 2005, 49, (2), 98 R. Seymour, Platinum Metals Rev., 2006, 50, (1), 27 ® Thomson Reuters, Scientific: Products: Aureka : http://scientific.thomsonreuters.com/products/aureka/ World Intellectual Property Organization, IP Services, WIPO International Classifications:

5 6 7

http://www.wipo.int/classifications/ J. A. G. Williams, Platinum Metals Rev., 2007, 51, (2), 85 R. J. Potter, Platinum Metals Rev., 2008, 52, (3), 155 ® CAS, STN AnaVistTM: http://www.cas.org/products/anavist/

The Author Richard Seymour is the Head of Technology Forecasting and Information at the Johnson Matthey Technology Centre, U.K. He is interested in the use of information in the areas of competitive intelligence and commercial development.

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