The opinion of the court was delivered by: SCULLIN
MEMORANDUM-DECISION AND ORDER
This is an action for patent infringement. The Plaintiff, Canton Bio-Medical, Inc., alleges that the Defendant's patent, U.S. Patent No. 5,647,939 ("the '939 patent"), and other related processes infringe their patent, Patent No. 4,499,148 ("the '148 patent"). Presently before the Court is the Defendant Integrated Liner Technology, Inc.'s ("ILT's") motion for summary judgment brought pursuant to Rule 56 of the Federal Rules of Civil Procedure. Defendant argues that its accused process does not infringe the Plaintiff's patent as a matter of law based on the application of prosecution history estoppel.
Oral argument was held on May 8, 1998, at which time the Court reserved decision on the Defendant's motion and authorized the parties to submit additional briefing.
Both Plaintiff and Defendant manufacture products called septa. Septa are small laminated rubber discs which are used in the pharmaceutical and medical industries for self-sealing vial caps which permit the insertion of a hypodermic needle without contaminating the inside of the vial. Both parties' products consist of a silicone rubber component which is fused to a polyolefin plastic component.
History of Plaintiff's '148 Patent
In their motion, the Defendant focuses on Claim 1 of the '148 patent, as its elements are incorporated into all the other claims of the patent. Claim 1 reads:
1. A method of chemically bonding elastomeric materials to chemically inert polyolefins, the method comprising:
(a) exposing a chemically inert polyolefin surface to a corona discharge treatment,
(b) applying to the corona discharge treated surface of the polyolefin a primer solution of ethyl silicate, ethyl ortho silicate and tetra butyl titanate in an organic solvent,
(c) placing the treated and primed surface of polyolefin in contact with the surface of an uncured elastomeric compound of molecular weight above 61,000 with a minimum elongation modulus of fifth percent; and
(d) applying heat to the composite material to cure the elastomeric compound article firmly together whereby upon curing of the elastomeric material the polyolefin will be firmly and securely bonded thereto.
In plain language, this patent refers to a process which chemically bonds silicone rubber to plastic. The Plaintiff's process entails taking the "polyolefin" surface, which in the case of the Plaintiff's product is the inner surface of a plastic cap, and exposing it to a "corona discharge treatment." A corona discharge is a type of electrical treatment which slightly alters the molecular structure of the surface of the plastic. After the corona treatment, the Plaintiff applies a primer of ethyl silicate, ethyl ortho silicate and tetra butyl titanate to the surface. The process then requires the application of an "uncured elastomeric compound," which is simply uncured silicone rubber, to the treated surface of the plastic. Heat and pressure are applied which trigger a chemical reaction causing the molecules of the plastic to bond with the molecules of the rubber, and also causing the silicone rubber to cure or harden. The ethyl and ethyl ortho silicates act as a sort of a molecular glue and the tetrabutyl titanate acts as a catalyst, promoting a reaction between the surface of the silicone rubber and the plastic. The end result is a plastic cap with a hardened or "cured" silicone rubber "septum" fused on the inside surface. This process is used to make cap/closures for sealed medical vials, and also to create plastic/rubber catheters.
The Plaintiff originally applied for a patent on this process on January 10, 1983. The Plaintiff, in its application, made reference to the fact that the process of bonding silicone rubber to plastic using corona discharge treatments had already been contemplated by prior patented processes (the Hurst '368 Patent). However, Plaintiff's application distinguished the Hurst '368 patent from its process on the basis that the "Hurst" process did not utilize a primer to promote adhesion between the silicone rubber and the substrate, and did not use uncured silicone rubber.
On February 22, 1984, the Plaintiff's patent application was rejected as being obvious in light of prior art. See 35 U.S.C. § 103. In support of their rejection, the patent office cited the "Hurst" patent as well as the "Stevenson" patent, "Young" patent, "McBride" patent, and the "Hamada" patent as relevant prior art which rendered the Plaintiff's patent obvious.
The action report stated as follows: (1) that the "Hurst" patent:
teaches the corona discharge treatment of elastomers or polyolefins (such as polyethylene) to increase adhesion. He also teaches the process of bonding an elastomeric material to a polyolefin film using primer.
(2) the "Stevenson" Patent:
teaches a method of bonding elastomeric material (preferably, silicone rubber) to substrates via the use of primers. He specifically recites the use of ortho silicates and silanes as components of the primer solution. He also teaches the bonding process prior to the curing of the elastomeric material. Further he recommends pretreatment of the substrate prior to the application of the primer.
teaches a similar method of bonding silicone rubber to substrates using a primer comprising a mixture of titanate and silicates in an organic solvent ... He also teaches the process of bonding prior to curing the elastomer.
(4) the "McBride" patent:
teaches as notoriously known in the art the bonding of polyolefins to a silicone resin by means of a primer 'chemically similar to ...