Minnesota Mining & Manufacturing Co. v. United States Rubber Co.

279 F.2d 409, 3 Fed. R. Serv. 2d 909
CourtCourt of Appeals for the Fourth Circuit
DecidedMay 16, 1960
DocketNos. 8048, 8049
StatusPublished
Cited by3 cases

This text of 279 F.2d 409 (Minnesota Mining & Manufacturing Co. v. United States Rubber Co.) is published on Counsel Stack Legal Research, covering Court of Appeals for the Fourth Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Minnesota Mining & Manufacturing Co. v. United States Rubber Co., 279 F.2d 409, 3 Fed. R. Serv. 2d 909 (4th Cir. 1960).

Opinion

SOPER, Circuit Judge.

The appeals in these two cases bring before us again United States Reissue Patent No. 23,843 for an adhesive insulating tape issued to R. J. Oace and others, assignors to Minnesota Mining and Manufacturing Company, which we considered initially, and on rehearing in Sears, Roebuck & Co. v. Minnesota Mining & Mfg. Co., 243 F.2d 136 and 249 F.2d 66. The trial court in the earlier case had found for Minnesota on the issue of infringement based on the sale by Sears, Roebuck and Company of tape manufactured by Plymouth Rubber Company, Inc., a codefendant, which controlled the defense of the suit; but after careful consideration of the scope of the patent and of the elements of the claims, we reached the conclusion that the defendants had not infringed the patent since one of the elements of the patented structure had been omitted in the manufacture of the accused product.

On rehearing we adhered to this decision and rejected the motion of the plaintiff to send the case back to the District Judge to consider newly discovered evidence since we were of the opinion that the new evidence, if accepted, did not require a change in our decision on the issue of infringement.

The instant suits on the same patent were brought by Minnesota after the favorable decision of the District Court in Sears (Minnesota Mining & Mfg. Co. v. Sears, Roebuck & Co., D.C., 141 F.Supp. 686) but before its reversal on appeal, the suit against United States Rubber Company being instituted on June 15, 1956, and that against Goodyear Tire and Rubber Company on July 5, 1956; but the trial of the suits was stayed pending the appeal in the case against Sears. They were, however, brought to the attention of the District Judge by motion for summary judgment filed by the defendants on August 10, 1959, after our decision in the Sears case and after infringement suits on the same patent brought by Minnesota against other defendants in other sections of the country had terminated unsuccessfully.1

[411]*411In support of the motions for summary judgments in the instant suits the defendants filed affidavits in which it was shown that the accused articles sold or used by the defendants were not manufactured by them but by Plymouth, the codefendant in charge of the defense of the suit against Sears. The affidavits further showed that the ingredients of the product sold by the defendants were the same as those used in the tape sold by Sears. Counter-affidavits were filed by Minnesota; but the District Judge, in considering the affidavits on both sides, granted the motions for summary judgment and dismissed the suits since he reached the conclusion that the affidavits raised no substantial issue of fact.

Minnesota strongly contends that the summary dismissal of the instant cases was erroneous because the affidavits filed by the parties raise a genuine issue of fact as to whether the tapes sold by the defendants prior to the filing of the suits against them were substantially the same in structure as the tapes which in Sears were held not to infringe the patent. For an understanding of the point we must restate, in substance, what was decided in the Sears case in regard to the composition of the patented structure. As our first opinion points out, 243 F.2d 136, the patent specifies an adhesive insulating tape composed of a film backing mixed with a non-volatile liquid plasticizer and a soft and resinous plasticizer, together with an adhesive coating united to the inner surface of the backing. The inventor stressed the fact that the finished article would not possess the desired qualities unless both a liquid and a resinous plasticizer were used in its manufacture. The specifications expressly stated (243 F.2d 138) that, in order to secure permanent equilibrium between the backing and adhesive, it was necessary to use with the film backing a combination of modifiers, including a substantial but minor amount of a low-molecular-weight liquid plasticizer, together with a substantially equal or somewhat greater amount of a high-molecular-weight resinous type plasticizer; and it was pointedly emphasized that the desired results could not be obtained by the use of resinous or high-molecular-weight modifiers alone. [Emphasis supplied.] Thus it was said (243 F.2d 138, 139):

“* * * js surprisingly found that these [resinous] materials do not provide for permanent equilibrium of adhesive and backing as herein defined. Instead, it has been shown that pressure-sensitive adhesives in prolonged contact with highly stretchable and elastic films consisting solely of vinyl polymer and resinous modifier lose a great deal, if not all, of their initial tackiness or pressure-sensitivity. When tape made in this way is unwound from roll form, after a moderate period of storage, and applied to a splice, it does not adhere either to the electrical conductor or to its own backing, and hence is of no value as an insulating and protective coating.”

Based on this disclosure, typical claim 1 of the patent declares that the patented tape is comprised of an elastic film backing formed of a homogeneous mixture consisting of a blend of (1) a major proportion of vinyl chloride, (2) a substantially non-volatile liquid phytalyl ester plasticizer, (3) a soft and viscous low-acid-number alkyd plasticizer resin in amount at least equal to the amount of the liquid plasticizer, and (4) a pressure-sensitive rubber resin type adhesive coating united to the inner surface of the film backing.

The event showed, however, that the patentees were in error in supposing that both kinds of plasticizers were needed in order to produce a satisfactory tape. Plymouth, experimenting in the field, found that by using only a resinous [412]*412plasticizer such as G-40, or its substantial equivalent G-25, satisfactory results could be obtained and it accordingly placed a tape so made on the market which was sold by Sears and other persons who were sued by Minnesota for infringement. In the prosecution of these suits, Minnesota contended that even if Plymouth used only a resinous plasticizer, its tapes, nevertheless, infringed the patent because the resinous plasticizer employed contained a substantial quantity of more liquid molecular weight material, which was the equivalent of a liquid plasticizer. In our opinion we rejected this contention and stressed the significant differences between the two types of plasticizers in these words (243 F.2d 143):

“The evidence clearly shows that there are two well defined and distinctive types of plasticizers, as the language of the specification indicates, which are not only well recognized by the trade but are characterized by substantial differences in chemical composition. The liquid plasticizers are all monomeric, that is, they are simple, precise and well defined chemical compounds of low-molecular-weight ranging from 250 to 600. In them every molecule is like every other molecule so that the material cannot be fractioned. It is thinly fluid. DOP for example has a molecular weight of 390 and a viscosity of less than one poise, which is the unit by which viscosities are measured. Resinous plasticizers on the other hand are polymeric.

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279 F.2d 409, 3 Fed. R. Serv. 2d 909, Counsel Stack Legal Research, https://law.counselstack.com/opinion/minnesota-mining-manufacturing-co-v-united-states-rubber-co-ca4-1960.