Sandvik Intellectual Property AB v Kennametal UK Ltd

JurisdictionEngland & Wales
JudgeTHE HON MR JUSTICE ARNOLD,MR JUSTICE ARNOLD
Judgment Date15 December 2011
Neutral Citation[2011] EWHC 3311 (Pat)
Docket NumberCase No: HC10C02090
CourtChancery Division (Patents Court)
Date15 December 2011

[2011] EWHC 3311 (Pat)

IN THE HIGH COURT OF JUSTICE

CHANCERY DIVISION

PATENTS COURT

Royal Courts of Justice

Strand, London, WC2A 2LL

Before:

The Hon Mr Justice Arnold

Case No: HC10C02090

Between:
Sandvik Intellectual Property AB
Claimant
and
(1) Kennametal UK Limited
Defendants
(2) Kennametal Europe GMBH

Iain Purvis QC and Anna Edwards-Stuart (instructed by Charles Russell LLP) for the Claimant

Richard Meade QC and Andrew Lykiardopoulos (instructed by Bristows) for the Defendants

Hearing dates: 16-18, 21-24 November 2011

Further written submissions 8 December 2011

THE HON MR JUSTICE ARNOLD MR JUSTICE ARNOLD

Contents

Topic

Paragraphs

Introduction

1–2

General technical background

3–17

Cutting tools

3–5

Alumina coatings

6–12

CVD

13–14

X-ray diffraction

15–17

The skilled person or team

18–19

The witnesses

20–25

Common general knowledge

26–66

The Chatfield Paper

28–33

Alumina coated tools generally in 1992

34–36

CVD equipment

37

CVD processes for depositing alumina

38–39

Texture of alumina coated tools

40–42

XRD

43–66

PDF cards

44–54

Ka2 stripping

55–61

Thin film correction

62–64

Other matters

65–66

The Patent

67–82

The claims

83–88

Construction

89–89

Consisting of single phase a-structure

92–95

A texture coefficient (TC) larger than 1.3, preferably larger than 1.5

96–105

Insufficiency: the law

106–124

Classical insufficiency

109–118

Ambiguity

119–119

Excessive claim breadth

121–124

Insufficiency: the facts

125–169

Classical insufficiency

126–161

Reproducibility of Example 1

126

Kennametal's experiment

127–138

Sandvik's experiment

139–145

Conclusion on Example 1

146–147

Sufficiency across the breadth of claim 6

148–160

Conclusion

161

Ambiguity

162–165

Excessive claim breadth

166–169

Lack of novelty

170–172

Obviousness

173–200

The prior art relied upon

175–176

Obviousness of claim 6

177–196

The specification

187–190

Subsequent evidence

191–195

Conclusion

196

Obviousness of claim 7

197–200

Infringement

201–212

Conclusions

213

Introduction

1

In these proceedings the Claimant ("Sandvik") claims that the Defendants ("Kennametal") have infringed European Patent (UK) No. 0 603 144 ("the Patent") entitled "Oxide coated cutting tool". The oxide in question is alumina (Al 2O 3). In fact, claim 1 of the Patent is not limited to cutting tools (that limitation only comes in claim 6), but for all practical purposes this case is about cutting tools. Kennametal denies infringement and counterclaims for revocation on the grounds of lack of novelty, obviousness and insufficiency. Sandvik has made a conditional application to amend claim 1 of the Patent. There is no challenge to the claimed priority date of 18 December 1992.

2

There is parallel litigation in Germany and the USA. This is relevant for two reasons. First, Kennametal rely by way of hearsay notice on evidence given by three Sandvik witnesses given in US depositions. Secondly, Sandvik relies on the judgment of the Landgericht Düsseldorf dated 1 December 2011 upholding Sandvik's claim for infringement of the German counterpart of the Patent. So far as the latter point is concerned, Kennametal point out that the Düsseldorf Court did not have the validity issues before it, nor did it have a lot of the evidence before this court.

General technical background

Cutting tools

3

A cutting tool is a tool that is used to remove material from a workpiece by means of shear deformation. Cutting tools must be made from a material harder than the material which is to be cut, and must be able to withstand the heat generated in cutting. Chip forming machining is a general term for machining processes in which a tool is used to remove material from the workpiece in the form of discrete chips or ribbons (also known as swarf):

4

Machining tools for use in milling and turning operations commonly have one or more lozenge—shaped "inserts" with up to four usable cutting edges:

5

Inserts of the kind to which this action relates generally consist of a cemented carbide (or other carbide) substrate, a titanium carbide, carbonitride or nitride (TiC, TiCN or TiN) layer and a layer of alumina. The reasons for the choice of alumina as a coating include its hardness and high melting point. Such tools are typically made by chemical vapour deposition ("CVD").

Alumina coatings

6

Alumina coatings for cutting tools have a number of characteristics relevant to the current dispute. The first is thickness measured in µm (microns). In 1992, alumina layers would typically range from 1 to 10 microns thick, but it was possible to deposit thicker layers.

7

The second is phase. This refers to the long-range order of the atoms. Some materials can exist in different phases. Alumina can exist in a number of different phases, identified by the Greek letters a, ?, d, ?, ?, ? and ?. These are all crystalline phases i.e. they have a particular long-range order. The two phases which are most relevant to the present case are a and ?. a-alumina (corundum) is the most thermodynamically stable phase. ?-alumina is metastable, and at high temperatures it transforms to a-alumina. In addition, alumina may be amorphous, that is to say, having no long range order.

8

The third characteristic is grain size expressed in µm. This is a measure of the size of individual alumina crystal grains. When alumina nucleates on a substrate, alumina nuclei will form. A nucleus is a collection of atoms of a material which one is interested in depositing and which is large enough to support growth rather than spontaneously disappear. The nuclei are islands of crystal which eventually join together, forming grains. In 1992 it was well known that the grain size of the coating should be minimised to deliver high hardness and toughness and to produce a smooth coating surface which reduces cutting forces and improves the surface finish on the workpiece after cutting.

9

The fourth characteristic is texture. This refers to the orientation of the individual crystals. Not all the individual crystals in a coating will be in the same orientation, and often there will be a mixture of orientations. Crystal planes are defined by a notation system called Miller indices, integers represented by the letters hkl. Each plane is identified by three indices written as (hkl), for example (001). (Sometime a fourth index is included as well, but it is not necessary to go into this.) There are over 50 different crystal planes for alumina. A crystal is said to be oriented in the (001) direction when it is oriented in the direction normal to the (001) crystal plane. This means that the (001) crystal plane is parallel to the substrate and the growth direction is normal to the (001) plane. In this figure the direction of growth is shown by the arrow:

10

Similarly, a crystal is said to be oriented in the (012) direction when it is oriented in the direction normal to the (012) crystal plane. This means that the (012) crystal plane is parallel to the substrate and the growth direction is normal to the (012) plane:

11

Texture can be expressed by a number referred to as the texture coefficient or TC (also referred to as T*). This is calculated using a mathematical formula known as the Harris formula. This is set out in the Patent and I reproduce it below. In essence, it gives the ratio of the orientation in question to the average orientation. This is calculated from X-ray diffraction measurements, as to which see below. In the Patent, only six orientations are measured, namely (012), (104), (110), (113), (024) and (116). Thus the results might be:

TC(012) =

1.4

TC(104) =

1.5

TC(110) =

0.6

TC(113) =

1.0

TC(024) =

0.9

TC(116) =

0.6

12

The values add up to 6, and so the average is 1. If any plane had a value of 6, that would mean that all of the crystals were oriented in that plane when compared with the other five planes specified in the Patent (although other crystals might be orientated in planes not specified). A value of 0 would mean that none of the crystals were in that plane. A value of 1.0 in each plane would indicate a truly random sample (among the planes specified in the Patent). In the example given, it can be seen that the texture coefficient in the (012) direction is 1.4, indicating some degree of preference for that orientation. The texture coefficient in the (104) direction is 1.5, indicating a slightly higher degree of preference for that orientation.

CVD

13

CVD is a common technique for the deposition of coatings. It was the only commonly known technique for deposition of alumina coatings on cutting tools in 1992. In the CVD process the coating is generated in situ by the reaction of gases. Usually, volatile molecular species are transported in the vapour phase to a heated substrate where adsorption and reaction occur to deposit a solid coating. A typical CVD system will thus contain a vapour production system, a reactor chamber which contains the samples to be coated and an effluent treatment system. Deposition typically occurs at or below atmospheric pressure.

14

Alumina is usually deposited by reacting aluminium trichloride (AlCl 3) with water generated from hydrogen and carbon dioxide by the water gas shift reaction:

H 2 + CO 2 H 2O + CO

2

AlCl3 + 3 H2O -> Al2O3 + 6 HCl

X-ray diffraction

15

X-ray diffraction is a convenient non-destructive analysis technique that has been widely...

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1 firm's commentaries
  • IP Bulletin - Winter issue - 21 February 2012
    • United Kingdom
    • Mondaq United Kingdom
    • 2 March 2012
    ...and the burden of proof for a positive case for non-infringement. Sandvik Intellectual Property AB v Kennametal UK Ltd and another [2011] EWHC 3311 (Pat), 15 December The High Court has held that a patent relating to alumina coatings for cutting tools was invalid on the ground of insufficie......

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