The United States Patent and Trademark Office (PTO) Board of Patent Appeals and Interferences (Board) affirmed the PTO’s rejection of claims 1-20 of Kenneth Harris and Jacqueline B. Wahl’s (collectively Harris) U.S. Patent Application 09/797,326 (’326 Application) as obvious under 35 U.S.C. § 103. Ex Parte Harris, Appeal No.2003-1930, Paper No. 16 (B.P.A.I. Sept. 26, 2003) (Paper No. 16). The Board found a prima facie case of obviousness because the claimed ranges overlapped the ranges disclosed in U.S. Patеnt No. 5,611,670 (issued Mar. 18,1997) (Yoshinari) and found Harris’s rebuttal evidence unpersuasive. Because substantial evidence supports the Board’s factual findings and the Board’s conclusion of obviousness was correct, this court affirms.
I.
On March 1, 2001, Harris filed the ’326 Application claiming a nickel-based super-alloy for turbine engine blades that experience high temperatures. The alloy disclosed in the ’326 Application contains nickel, plus twelve additional elements defined by a range of weight percentages. Representative claim 1 reads:
A nickel-base superalloy comprising, in percentages by weight, from about 4.3% to about 5.3% Chromium (Cr), from about 9.0% to about 10% Cobalt (Co), from about 0.6% to about 0.8% molybdenum (Mo), frоm about 8.4% to about 8.8% tungsten (W), from about 4.3% to about 4.8% tantalum (Ta), from about 0.6% to about 0.8% titanium (Ti), from about 5.6% to about 5.8% aluminum (Al), from about 2.8% to about 3.1% rhenium (Re), from about 0.9% to about 1.5% hafnium (HD, from about 0.06% to about 0.08% carbon (C), from about 0.012% to about 0.020% boron (B), from аbout 0.004% to about 0.010% zirconium (Zr), the balance being nickel and incidental impurities.
The ’326 Application discloses a single embodiment of the claimed alloy — CMSX®-486. The ’326 Application’s specification indicates that CMSX®-486 has improved *1341 stress-rupture properties over other alloys. The PTO made alternative rejections of representative claim 1 as being prima facie obvious in view of Yoshinari or U.S. Patent No. 5,069,873 (issued Dec. 3, 1991) (the ’873 patent). 1
The PTO rejected all рending claims in an Office Action dated August 7, 2002. The Board affirmed. Paper No. 16. The Board granted Harris’s request for reconsideration but made no changes to the original decision. Ex Parte Harris, Appeal No.2003-1930, Paper No. 18 (B.P.A.I. Feb. 4, 2004). Harris now appеals to this court. This court has jurisdiction under 28 U.S.C. § 1295(a)(4)(A).
II.
The ultimate determination of obviousness under 35 U.S.C. § 103 is a legal conclusion based on underlying findings of fact.
In re Kotzab,
The PTO has the burden of showing a prima facie case of obviousness.
Mayne,
In this case, the Board found a prima facie case of obviousness because the ranges of the invention of Yoshinari overlap the ranges of representative claim 1. Paper No. 16, slip. op. at 7. As shown in the table below, not only do Yoshinari’s disclosed ranges overlap all twelve of the ’326 Application’s claimed ranges, but eleven of Yoshinari’s disclosed ranges completely encompass Harris’s claimed ranges. Only Yoshinari’s chromium range (5.0— 14.0) does not completely encompass thе ’326 Application’s chromium range (4.3 — 5.3) (in percentages by weight).
*1342 Element Claimed Range Yoshinari
Chromium (Cr) about 4.3-about 5.3 5.0-14.0
Cobalt (Co) about 9-about 10 Up to 10.0
Molybdenum (Mo) about 0.6-about 0.8 Up to 6.0
Tungsten (W) about 8.4-about 8.8 2.0-15.0
Tantalum (Ta) about 4.3-about 4.8 Up to 12,0
Titanium (Ti) about 0.6-about 0.8 0.5-5.0
Aluminum (Al) about 5.6-about 5.8 4.0-7.0
Rhenium (Re) about 2.8-about 3.1 Up to 4.0
Hafnium (Hf) about 0.9-about 1.5 Up to 2.0
Carbon (C) about 0.06-about 0.08 0.05-0.20
Boron (B) about 0.012-about 0.020 Up to 0.035
Zirconium (Zr) about 0.004-about 0.010 Up to 0.035
Nickel (Ni) Balance Balance, 58% or more
Yoshinari, col. 8, 1. 20 — col. 9, 1. 16. In addition, even the narrower ranges taught by Yoshinari’s preferred embodiments and examples overlap eleven of the twelve claimed rangеs. Again, the chromium ranges disclosed in Yoshinari’s preferred embodiment (5.5 — 9.0) and one of its examples (5.5 — 7.0) do not overlap the ’326 Application’s chromium range (4.3 — 5.3).
Yoshinari Yoshinari Yoshinari Element Claimed Range_Preferred_Ex. 1_Ex. 2
Cr_about 4.3-about 5.3_5.5-9.0_5.5-7.0_5.0-14,0
Co_about 9-about 10_9-10.5_9-9.5_0-12,0
Mo_about 0.6-about 0.8_0.3-1_0.3-0.7_0.5-3.0
W_about 8.4-about 8.8_8-11_8^9_5.0-12,0
Ta_about 4.3-about 4.8_3^4_3^4_3.0-7.0
Ti_about 0.6-about 0.8_0.5-1_0.5-0.9_0.5-3.0
Al_about 5.6-about 5.8_5^6_5.5-6.0_4.0-6.0
Re_about 2.8-about 3.1_2.5-3.5_2.8-3.1_0-3.5
Hf_about 0.9-about 1.5_0.5-1_0.7-1.0_0-2.0
C_about 0.06-about 0.08_0.03-0.1_0.05-0.1_Formula
B_about 0.012-about 0.020 0.005-0.25 0.005-0.01 Formula
Zr_about 0.004-about 0.010 0.005-0.25 0.005-0.01 Formula
Nb_None_0,2-3_None_None
Ni_Balance>58%>58%>58%
Yoshinari, col. 8,1. 20 — col. 9,1. 16; col. 10, 11. 13-19. The Board explained that from the description of Yoshinari
a person of ordinary skill in the art would have reasonably expected that the chromium content affects the hot corrosion resistance of the suрeralloy and cobalt content affects the hot corrosion resistance and the high temperature strength of the superalloy. Thus, a person of ordinary skill in the art would have recognized the suitability of adjusting the content of thе disclosed elements within the disclosed ranges.
Paper No. 16, slip. op. at 7.
Harris points to
Peterson
to advance his position that Yoshinari’s ranges are too
*1343
broad to teach any specific alloy to the skilled artisan.
Peterson
discussed that a disclosed range might become too broad to teach a subset range.
In addition,
Peterson’s
claimed ranges were narrower than those claimed in this case. Seven of the ten alloys claimed in
Peterson
were defined by a specific value.
When the PTO shows prima facie obviousness, the burden then shifts to the applicant to rebut.
In re Dillon,
Harris argues that Yoshinari teaches away from the claimed range of the invention. In support оf this contention, Harris argues that nothing in the Yoshinari patent suggests the use of less chromium and more tantalum, namely the claimed ranges of about 4.3% to 5.3% chromium and about 4.3% to 4.8% tantalum. To the contrary, Yoshinari’s Example 2 teaches a suрeral-loy having tantalum content from “3.0 to 7.0” percent, which completely encompasses the claimed range of tantalum. Yoshi-nari, col. 10, 11. 13-19. In addition, Yoshi-nari teaches that 5-14 weight percent is an “appropriate аdditive amount” of chromium. Id. at col. 8, 11. 33-37. Thus, Yoshi-nari teaches that a portion of the claimed range (e.g., 5.0-5.3) is “appropriate.” Finally, the ’326 Application’s use of the term “about” shows that the applicants did not intend to limit the claimеd ranges to then-exact end-points. See Jeneric/Pentron, Inc. v. Dillon Co. 205 F.3d 1377, 1381 (Fed.Cir.2000). Thus, contrary to Harris’s contention, Yoshinari’s preferred range of 5.5 to 7.0 is not necessarily outside the scope of “about 5.3.” Therefore, this court finds substantial evidence supports the Board’s finding that Yoshinari does not teach away.
With respect to unexpected results, the Board concluded that Harris had not shown that any results were unexpected. Paper No. 16, slip. op. at 11-12. As evidence of unexpected results, Harris compares CMSX®-486, an alloy centrally located within claim l’s range, to four commercial alloys, namely CM247LC, CMSX-3, CM186LC and CMSX-681. All are prior art except CMSX-681. When compared to CM186LC, CMSX®-486 *1344 shows 32% to 43% improvement in stress rupture life. Harris argues CM186LC is the closest prior art because it differs from the claimed invention only in that it has 6.0% chromium rather than about 4.3% to 5.3%, and 3.4% tantalum rather than about 4.3% to 4.8%. While the results were not as favorable when compared against CMSX-3, Harris argues CMSX®-486 can be рroduced at considerable cost savings as compared with single crystal castings of CMSX-3 because of fewer rejectable grain defects.
The 32-43% increase in stress-rupture life, however, does not represent a “difference in kind” that is required to show unexpected results.
See In re Huang,
The Board also correctly reasoned that the showing of unexpected results is not commensurate in scope with the degree of protection sought by the claimed subject matter because the elemental composition of CMSX®^186 is at or near the midpoint of the claimed range. While Harris’s evidence may show a slight improvement over some alloys, the record does not show that the improved performance would result if the weight-percentages were varied within the claimed ranges. Even assuming that the results were unexpected, Harris needed to show results covering the sсope of the claimed range. Alternatively Harris needed to narrow the claims.
Finally, substantial evidence supports the Board’s finding that Harris did not compare an embodiment representative of the claimed range to аn embodiment of the closest prior art. Paper No. 16, slip. op. at 11-12. As stated above, Harris contends CM186LC is the embodiment closest to the prior art. However, because both CM186LC and CMSX®-486 have at least one element that is within Yoshinari’s general range, but outside a preferred range, CM186LC is no closer to the prior art than is CMSX®-486. In other words, CMSX®-486, the embodiment allegedly exhibiting unexpected results, is as equally representative of the prior art as is CM186LC. Whereas each embodiment is equally representative of the prior art, a comparison of those two embodiments cannot be said to establish that one embodiment has results unexpectedly superior over the prior art.
III.
In sum, this court affirms the Boаrd’s finding of a prima facie case of obviousness because the ranges claimed in the ’326 Application’s overlapped the ranges disclosed in Yoshinari. This court also sustains the Board’s finding that Harris’s rebuttal evidence was unpersuasive.
COSTS
Each party shall bear its own costs.
AFFIRMED
Notes
. The Patent and Trademark Office rejected claims 1-15 and 17-20 in light of Yoshinari, claim 16 in light of Yoshinari and U.S. Patent No. 6,074,602 (issued June 13, 2000) (Wuku-sick), and claims 1-10 in light of the '873 patent. Because this court affirms based on Yoshinari, it does not address the Board's alternative rejection based on the '873 patent. Harris did not appeal the rejection of claim 16.