【Volume 129】

In Taiwan patent practice, argument of teaching away has always been difficult to be accepted; a prior art may not be considered as teaching away from the invention unless it explicitly excludes the use of specific technical features. However, if a technical content is described as a comparative example with poor efficacy in the specification of the prior art, can it be concluded that a person ordinarily skilled in the art would not be motivated to make further improvements to the comparative examples in order to complete the invention of patent in dispute? The Taiwan Intellectual Property and Commercial Court (IP Court) expressed the latest opinion in the judgment of Lubrizol Advanced Materials, Co., Ltd. (US) v. Badische Anilin & Soda-Fabrik Ltd. (Taiwan), and clarified that determining an inventive step of an invention shall be based on whether the invention could be readily accomplished by a person ordinarily skilled in the art according to the technical content of the prior art, regardless of whether the cited prior art is a failed comparative example.

Case Fact

Lubrizol Advanced Materials, Co., Ltd. (the patentee and plaintiff, “Lubrizol”) is the owner of the Taiwan Invention Patent No. I523980 entitled “HIGH STRENGTH FABRICS CONSISTING OF THIN GAUGE CONSTANT COMPRESSION ELASTIC FIBERS AND METHOD FOR PRODUCING THE SAME” (‘980 patent). On July 4, 2019, Badische Anilin & Soda-Fabrik, Ltd.(“BASF”) filed an invalidation action against the ‘980 patent and the TIPO rendered a decision that “claims 1-9, 11-16 are invalidated, thereby shall be revoked”, and “the invalidation action against claims 10, 17 to 19 is rejected”. Dissatisfied with some claims being invalidated in the original decision, the plaintiff filed a petition, and then lodged an administrative appeal after the petition was dismissed. However, the IP Court also invalidated claims 1-9 and 11-16 with the same reason of lacking an inventive step and upheld the appeal decision (2022 Xingzhuansuzi No. 22 Judgment).

Technical Analysis of Claim 1 of the ‘980 patent and Exhibit 2

The ‘980 patent provides a thin gauge, constant compression, high strength fiber having an ultimate elongation of at least 400%, and having a relativity flat and/or constant modulus in the load and unload cycle between 100% and 200% elongation.

Claim 1 of the ‘980 patent describes:

A melt spun elastic fiber made from cross-linked thermoplastic polyurethanes, wherein the fiber has an ultimate elongation of at least 400% and stress values in the load cycle of:

(1) less than 0.023 gram-force per denier at 100% elongation;

(2) less than 0.036 gram-force per denier at 150% elongation; and

(3) less than 0.053 gram-force per denier at 200% elongation;

wherein the melt spun elastic fiber has stress values in the unload cycle of: 

(1) less than 0.027 gram-force per denier at 200% elongation; 

(2) less than 0.018 gram-force per denier at 150% elongation; and

(3) less than 0.015 gram-force per denier at 100% elongation; and

wherein the thermoplastic polyurethane is made from a mixture, comprising:

(a) a linear hydroxyl terminated polyester having a number average molecular weight of 500 to 10,000; 

(b) a polyisocyanate; and

(c) a diol chain extender having 2 to 10 carbon atoms. 

Exhibit 2 is a European Invention Patent No. 1639026 entitled “Melt spun polyether tpu fibers having mixed polyols and process” (EP1639026A1).

Example 6 of Exhibit 2 is a comparative example and disclosed the main technical features of the ‘980 patent. The only difference is that Example 6 of Exhibit 2 discloses that “the Example showed a stress value equal to 0.018 gram-force per denier in the unload cycle at 150% elongation”, while claim 1 of the ‘980 patent discloses less than 0.018 gram-force. Moreover, Exhibit 2 discloses that “the Example showed a stress value equal to 0.015 gram-force per denier at 100% elongation”, while claim 1 of the ‘980 patent discloses less than 0.015 g-force. However, the stress values in the ‘980 patent are very similar to those in Exhibit 2. 

Example 5 of Exhibit 2 is an implementation example, the only difference between Example 5 of Exhibit 2 and Claim 1 of the ‘980 patent is that Example 5 of Exhibit 2 does not directly disclose the stress values in the unload cycle described in claim 1 of the ‘980 patent, and Example 5 of Exhibit 2 uses a polyether intermediate, instead of a polyester intermediate, to synthesize TPU (i.e., the thermoplastic polyurethane of the ‘980 patent). That is, Example 5 of Exhibit 2 does not disclose the linear hydroxyl terminated polyester of claim 1 of the ‘980 patent.

Accordingly, the issue in this case is “May comparative examples of prior art be served as evidence denying an inventive step of the patent in dispute?” That is, would a person ordinarily skilled in the art be motivated to adopt a comparative example of a prior art with poor efficacy and improve it to complete the invention of the patent at issue?

Opinion of the IP Court

(1) The plaintiff asserted that: “Example 6 of Exhibit 2 is a comparative example. The specification of Exhibit 2 discloses that TPU in Example 6 is unable to withstand the dyeing cycle of polyester fibers, and the heat resistance thereof is too low to be combined with polyester fibers to produce elastic fibers, which is actually contrary to the purpose of the invention of the ‘980 patent for producing clothing.”

However, the IP Court deemed that paragraph [0053] of Exhibit 2 describes that the fiber can be used to make fabrics such as underwear, sportswear, etc., and a person ordinarily skilled in the art would know that the fabrics made of this fiber should have a considerable degree of comfort, and it is difficult to conclude that Exhibit 2 is inconsistent with or contradictory to the purpose of the invention of the ‘980 patent. In addition, claim 1 of the ‘980 patent only defines the subject matter as “melt spun elastic fiber”, and does not further define the fiber to be an elastic fiber formed by combining with polyester fiber. Therefore, it does not exclude the elastic fiber formed only by TPU fiber.

(2) The plaintiff asserted that “Since the TPU in the example of Exhibit 2 could not be dyed, and undyed fabrics cannot be applied to market at all. A person ordinarily skilled in the art would know that Example 6 was merely a completely failed example of Exhibit 2, and would have no motivation to choose Example 6, which could not be dyed or applied, for further improvement. Therefore, Example 6 teaches away from the invention of the ‘980 patent.”. 

However, the IP Court deemed: 

1. From the description of paragraph [0075] of the specification of Exhibit 2, the original intention is to describe that the TPU of this Example 6 is unable to withstand the cyclic operation of the polyester fiber dyeing in the specific conditions of “130°C for 60 minutes” only. Moreover, since dye-free fabrics are produced without a use of dyes, they shall be able to alleviate the problems caused by dyes on the surface of the fabrics, and thus shall be favored by consumers with sensitive skin and those with environmental consciousness . It is hardly reasonable to conclude that the TPU of Example 6 inevitably will not be used for improvement by a person ordinarily skilled in the art due to lack of market applicability, and therefore Example 6 shall not be considered as teaching away from the ‘980 patent.
2. Furthermore, an inventive step of an invention shall be determined according to whether the invention could have been easily accomplished by a person ordinarily skilled in the art based on the technical content of the prior art. Even if the cited prior art or technical means are failed cases, examples/comparative examples, etc., shall not directly lead to the conclusion of lacking an inventive step. As long as the prior art disclosures show potential for research and development, and a person ordinarily skilled in the art is motivated to improve the prior art, the prior art may be the starting point of reinvention(innovation). In this case, the prior art is certainly suitable to serve as the basis for determining whether the invention has an inventive step.

(3) The plaintiff asserted that “Example 5 of Exhibit 2 and inventions defined in the aforementioned claims of ‘980 patent at least show differences regarding fiber material (polyether intermediate or polyester intermediate) and stress values in the unload cycle. A person ordinarily skilled in the art is unable to accomplish the invention of the ‘980 patent according to the TPUs of Example 5.”. 

However, the IP Court deemed that paragraph [0004] of Exhibit 2 has specifically described that the fibers can be produced from raw materials comprising polyether intermediates and polyester intermediates after reaction, and can be used to improve the properties of the TPU; in the same exhibit, it has been taught and suggested that the properties of the TPU can be improved by using a mixture of polyether intermediates and polyester intermediates as a raw material for reaction. Thus, in order to enhance the applicability of the TPU disclosed in Example 6, a person ordinarily skilled in the art would be motivated to try to use polyether intermediates and polyester intermediates in its raw materials to enhance its properties. Therefore, a person ordinarily skilled in the art shall be able to easily accomplish the invention as defined in claim 1 of the ‘980 patent by simple experimentation as practically needed.