In re Murch

• Decision Date: 19 October 1972
• Docket Number: Patent Appeal No. 8743.
• Citation: 464 F.2d 1051
• Court: U.S. Court of Customs and Patent Appeals (CCPA)
• Parties: Application of Lee Ellis MURCH.

464 F.2d 1051 (1972)

Application of Lee Ellis MURCH.

Patent Appeal No. 8743.

United States Court of Customs and Patent Appeals.

August 24, 1972.

Rehearing Denied October 19, 1972.

Edwin Tocker, Wilmington, Del., attorney of record for appellant; Gerald A. Hapka, Washington, D. C., of counsel.

S. Wm. Cochran, Washington, D. C., for the Commissioner of Patents; Raymond E. Martin, Washington, D. C., of counsel.

Before RICH, Acting Chief Judge, ALMOND, BALDWIN and LANE, Judges, and CLARK, Justice (Ret.), United States Supreme Court, sitting by designation.

LANE, Judge.

This is an appeal from the decision of the Board of Appeals affirming the 35 U.S.C. § 103 rejection of claims 1 through 8 and 10 of appellant's application for "Blends of Polyamides and Ionic Copolymer."¹ We affirm with respect to claims 1 through 8, but reverse with respect to claim 10.

Claim 1 is the broadest of the appealed claims and reads as follows:

1. A thermoplastic blend consisting essentially of an intimate mixture of from 50 to 99% by weight of a polyamide and, complementally, from 1 to 50% by weight of an ionic copolymer of units derived from an a -olefin of the formula RCH = CH2 wherein R is H or alkyl having from 1 to 8 carbon atoms and from 0.2 to 25 mole % of units derived from an a, ß -ethylenically unsaturated carboxylic acid, at least 10% of the acid groups of said acid being neutralized by metal ions.

The claims are drawn to a blend of (1) a polyamide, such as polyhexamethylene adipamide (claim 2), and (2) an ionic copolymer of (a) an alpha-olefin, such as ethylene (claim 5), and (b) an alpha-beta-ethylenically unsaturated carboxylic acid, such as methacrylic acid (claim 3) or maleic acid (claim 4), wherein at least 10 percent of the acid groups have been neutralized by metal ions, such as zinc (claim 6). The blend may additionally contain an antioxidant (claim 8), and claim 7 depends from claim 1 and defines the ionic copolymer as a random copolymer. Claim 10 depends from claim 7 and reads as follows:

10. The thermoplastic blend of claim 7 wherein from 60 to 85 per cent by weight of said blend is said polyamide with the remainder being said copolymer and from 1 to 8 mole % of said copolymer is said acid.

Two properties of blends such as those herein claimed are relevant to this appeal. Blend toughness refers to the toughness, i. e., the ability to withstand deformation without fracture, of a molded article composed of the blend. When an article is formed by injecting the molten blend into the forming mold from two sources, a weld line is formed at the juncture of the several masses. Such a weld line would also form whenever there is an obstruction in the molding chamber. The weld line apparently represents the weakest point in the molded article, and weld line toughness refers to the toughness of an article formed from the blend where a weld line is present. Blend toughness is measured on an article molded from the blend without a weld line.

Appellant asserts that the claimed blends exhibit a greater blend toughness than blends which differ only to the extent that none of the acid groups on the copolymer are neutralized. However, the improvement in blend toughness is not considered to be exceptional or unexpected. What appellant does urge is that weld line toughness is dramatically increased for the blend defined in claim 10 when at least 10 percent of the acid groups are neutralized and that this improvement is completely unexpected. In support of these contentions, appellant submitted a Rule 132 affidavit, and on this appeal, the solicitor does not challenge the sufficiency of that showing.² Hence as we consider the prior art, we do so with the understanding that neutralizing at least 10 percent of the copolymer acid groups produces no unexpected result with respect to blend toughness, but that insofar as the blend of appealed claim 10 is concerned, the weld line toughness is unexpectedly improved when the acid copolymer is partially neutralized.

The examiner and board relied upon Halliwell et al. (Halliwell)³ and Rees.⁴ Halliwell, the principal reference, discloses blends composed of a polyamide and an olefin-acid copolymer. The only difference between Halliwell's blends and appellant's resides in the neutralization of at least 10 percent of appellant's acid groups with metal ions. Rees discloses ionic olefin-acid copolymers and specifically teaches that the neutralization of at least 10 percent of the acid groups to render the copolymers ionic improves various copolymer properties, including toughness. The examiner reasoned that Rees provides ample suggestion for one of ordinary skill in the art to substitute the ionic copolymers for the nonionic copolymers in the Halliwell blend, and since the Halliwell blend so modified is appellant's claimed blend, the examiner rejected claims 1 through 8 and 10 under 35 U.S.C. § 103 as obvious from Halliwell and Rees. The board elaborated on the teachings in Rees which would suggest that the improvements in the copolymer would be carried over to a blend having as one of its components that copolymer. The examiner's rejection of the claims was sustained.

Appellant argues claims 1 through 8 separately from claim 10. With respect to the first eight claims, appellant contends that one of ordinary skill in the art would not be led to substitute the ionic copolymers disclosed by Rees for the copolymer component of the Halliwell blends. Appellant introduced a patent to Mesrobian et al. (Mesrobian)⁵ which discloses blends of a polyamide and a polyolefin such as polyethylene or polypropylene. Appellant claims that the Mesrobian blends lacked toughness and that Halliwell discovered that the substitution of an olefin-acid copolymer for the polyolefin of Mesrobian improves that property. Halliwell theorizes that the acid groups on the copolymer may react with the polyamide, and appellant presumes that this interaction is responsible for the improved toughness of the Halliwell blends as compared to the Mesrobian blends which lack the acid groups. Appellant's conclusion is that one of ordinary skill in the art would not neutralize any of the acid groups and thereby take away the constituents which when added improved the toughness of the composition. In short, appellant perceives a trend in blend developments toward increasing the number of acid groups in the blend. Appellant's neutralization step is contrary to the supposed trend and is urged to be unexpected, the Rees disclosure notwithstanding. As to claim 10, appellant contends that the uncontested showing of unexpected, superior weld line toughness is sufficient for patentability even if the blends are prima facie obvious from Halliwell and Rees.

OPINION

Claims 1 through 8

We agree with the solicitor that appellant's suppositions regarding the reaction between the acid groups on the copolymer and the polyamide and the role of that reaction in improving toughness are unsupported and speculative. We also agree that Halliwell and Mesrobian fail to establish any trend in the area of polymer blends. Appellant's case for a trend is built entirely about the Halliwell modification of the Mesrobian blend, and we think the solicitor is justified in questioning whether one of ordinary skill in the art would make the assumptions appellant makes only on the basis of Halliwell's discovery. In contrast to appellant's theory is the Rees disclosure which clearly points to the advantageous impact of partial copolymer neutralization on product properties. We do not think that one of ordinary skill in this art would be dissuaded from adopting the Rees improvement in polyamide-olefin-acid copolymer blends in the fear that some neutralization of the acid groups would necessarily result in a sacrifice of the improvements made by Halliwell. Rather, we are convinced that the reference teachings appear to be sufficient for the ordinary artisan having Halliwell and Rees before him to make the modification of Halliwell proposed by the examiner and board. The Patent Office has thereby made out a prima facie case of obviousness, In re Lintner, 458 F.2d 1013, 1016, 59 CCPA ___, ___ (1972), and in the absence of rebuttal evidence as to these claims, the decision of the board sustaining their rejection is affirmed.

Claim 10

We regard the subject matter of claim 10 to be prima facie obvious from Halliwell and Rees for the same reasons as claims 1 to 8. However, the uncontested fact is that the blend of claim 10 exhibits unexpectedly improved weld line toughness as compared to the Halliwell blends. We have previously held proof of such a fact to be persuasive rebuttal of the prima facie case. See In re Ackermann, 444 F.2d 1172, 58 CCPA 1405 (1971); In...