"Different Characteristics" Broadly Construed to Include Colored Plastic

In Sorensen, et al. v. International Trade Commission, et al. (Fed. Cir. October 31, 2005), the court construed the claim limitation "second plastic material having different characteristics than the first plastic material" to include mere differences in color. According to Circuit Justice Rader,

In this case, the language in claim [limitation] 1(e) requires that the first and second materials have "different characteristics." The claim does not limit these differences to any particular sub-set of the broad term "characteristics." In other words, according to the claim language any difference in characteristics between the two injected materials would satisfy the claim language. Thus, a difference in color alone would satisfy the "different characteristics" limitation. The color would be the characteristic that differs.

In the context of the invention, the primary point of a sequential molding method would seem to call for some differences in the separately molded materials. Obviously a product made of a single uniform material could be produced in a single molding step. As long as the sequential materials differ in some respect, however, the patent does not specify any particular characteristic that must differ to satisfy the "different characteristics" limitation. The breadth of the claim language suggests that any difference in characteristics justifies the sequential molding process. As long as the characteristics differ, the patent does not specify further the nature of the difference.

To reinforce this interpretation of the claim language, the specification of the ’184 patent states: "The first and second plastic materials may be either the same material or different materials." ’184 patent, col. 9, ll. 17-18. This passage emphasizes that the material injected into the molds may be "the same." This reference suggests again that the first and second injection could use plastic with the same molecular structure. In that case, the "different characteristics" limitation would require some difference other than molecular structure, such as color.

In the specification the inventor also offers examples of a number of characteristic differences in materials that would justify separate molding steps. One of these is transparency. See ’184 patent, col. 3, ll. 11-43. Differences in transparency, like differences in color, are differences that may or may not be associated with molecular structure. Thus, the inventor made clear in the examples as well that a
difference characterizable in terms other than molecular structure would satisfy
the "different characteristics" limitation. However, the inventor does not limit
the invention to these examples. In other words, the inventor does not disclaim,
in the specification or claims, any particular difference in characteristics of
the materials used in the sequential molding steps. In sum, the claim language
and the specification show that color differences would suffice to satisfy the
broad "different characteristics" limitation.

The prosecution history of the ’184 patent similarly shows no disavowal of claim scope in relation to material characteristics. The inventor amended claim 1 a number of times in response to rejections for obviousness over prior art. In the original application, claim 1(b) specified "injecting a first plastic material into the first mold cavity," and claim 1(e) specified "injecting a second plastic material into the second
mold cavity while the first plastic material component is contained therein." The examiner rejected claim 1 under 35 U.S.C. § 103 as obvious, citing U.S. Patent Nos. 4,422,995 (filed Dec. 7, 1981); 3,543,338 (filed Nov. 6, 1969); 3,832,110 (filed June 16, 1972); and 4,459,256 (filed March 22, 1982). To the examiner, these references would have made it obvious at the time of invention to use "the concept of a stabilizing region" in a multi-step molding process. In the rejection, the examiner noted that "the particular materials selected to be molded are a mere matter of choice depending on the product desired and are ofno patentable consequence to the claimed process." This comment showed that the examiner based the obviousness rejection upon stabilization in a multi-step process, not on the characteristics of the materials used in the injections.

On January 11, 1989, the inventor attempted to overcome the obviousness rejection by amending claim 1 to specify that the final product would require laminated walls. The inventor also modified steps 1(b) and 1(c) to specify that the first or second plastic material would be injected until it reaches the parting line between the common mold part and the complementary mold part. On April 27, 1989, the examiner again rejected the amended claims for obviousness over the same prior art.

On July 11, 1989, the examiner had a telephone interview with the inventor concerning the amended (and rejected) claim 1. The examiner’s record of this interview, in its entirety, is:

Discussed meaning of parting line and fact that two different materials with different properties are used. An amendment changing these limitations may not be entered.

Two weeks later the inventor filed a continuing application, amending claim 1 to include a requirement, in the preamble, that the molded product contain "a closed end and an open end terminating in a rim at the open end," and adding the phrase "having different characteristics than the first plastic material" to claim 1(e). The
inventor also amended the abstract with the addition: "A second plastic material
having different characteristics than the first plastic material is injected until it reaches the portion of the second mold cavity that defines the rim of the product to form a laminated wall." The inventor explained these changes as:

better distinguish[ing] the present invention over the art of record by defining a rim of the molded product, pointing out that both the injection of the first plastic material and the injection of the second plastic material reach the respective portions of the first and second mold cavities that define the rim of the product, and further pointing out that the first and second plastic materials have different characteristics.

The examiner then allowed the claims.

This final exchange between the inventor and the examiner during prosecution appears to have misled the administrative judge. Nevertheless, the exchange in no way shows a clear and unambiguous disavowal of the broad scope of the claim language. In other words, the prosecution history does not disavow the broad scope of the claim language and specification that permit any difference in characteristics, including color. See Omega Eng’g, Inc., 334 F.3d at 1324. On this record, this court perceives no disavowal of scope. The claim thus excludes no specific differences in characteristics, and in particular differences in color, in the molded materials.

However, according to the Administrative Law Judge's opinion, prior to the telephone interview and the amendment of the claims and specification, "the Examiner specifically rejected the notion that the injection molding of materials with different colors/transparencies was patentable, and explained at length in writing that injection molding with different colors/transparencies was well known in the art. . . To the contrary, based on the Examiner’s prior rationale for rejecting the claims, and the applicant’s subsequent argument that the claimed invention involves 'two different materials with different properties,' one of ordinary skill reading the prosecution history must conclude that the 'different characteristics' added to claim 1 pertains to differences other than color."

For those of you who are still unsure, here is the pertinent portion of the file history containing the Examiner's rejection (with emphasis added by the ALJ):

Claims 1-10 are rejected under 35 U.S.C. 103 as being unpatentable over Cooper [U.S. Patent No. 3,543,3381, Hehl [U.S. Patent No. 3,832,1101, or Zeigler [U.S. Patent No. 4,459,2561. Each of the cited references teaches the basic claimed method of two component injecting molding. It is submitted that the general product
configuration as claimed can be recognized in the three references.

Cooper teaches a method of producing a hollow plastic article having fused together panels of plastic materials. Cooper teaches that a frame is first molded on a mold core and then the platens are separated and the lower platen with the plastic frame being retained on the core is rotated on the core and moved together with another
mold. A second shot of injected plastic material into the cavity formed by the other mold cover on the core retaining the plastic frame results in a plastic article having
different plastic materials fused together (column 1, lines 3 1-3 8).

Hehl teaches a method of injection molding to form two color or two material objects using multiple cavities. In addition, Hehl teaches an injection mold whereby a parting line exists between the transporting plate and cavity plate. Ziegler teaches a method of injection molding to form a two component key-pad where the components used can be of the same or different color.

It is submitted the concept of a stabilizing region as claimed by the applicant is readable on the cited references. The references teach the general idea of using a first injected material to support part of the article in the mold before a second material in injected. As stated in the above rejection, the particular product shape and the particular shape of the various parts thereof are a mere matter of choice
of article design depending on the desired final product. * * * Finally it is submitted that the particular materials selected to be molded are a mere matter of choice as stated in the previous rejection. It is again noted that the use of transparent and nontransparent materials in making windowed articles is well known in the art and would have been obvious in each of the cited references depending on the desired end product.

It's all enough to make a lawyer want to move to Canada, where there is no doctrine of file history estoppel (and, perhaps, a higher threshold for appellate review.)