DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 4 – 6, 9, and 16 – 19 are rejected under 35 U.S.C. 103 as being unpatentable over CN112625221 to Lu et al. (hereinafter Lu) in view of JP 2005089572 to Inada et al. (hereinafter Inada). For the purposes of examination, citations for Lu and Inada are taken from machine translations of the respective documents obtained from the European Patent Office website in March 2025.
Regarding Claim 4. Lu teaches a process involving recycling polyester [0001]. The process involves obtaining bis(hydroxyethyl)terephthalate (BHET) from waste polyethylene terephthalate; followed by (1) feeding BDO/1,4-butanediol and then esterifying with BDO/1,4-butanediol into a reactor; and (2) additionally feeding BHET into the reactor [n0019] – [n0022]. Inada provides evidence that the reaction of BHET with BDO is a transesterification reaction which produces bis(4-hydroxybutyl)terephthalate (BHBT) [0008]. Thus, the process of preparing the intermediate in Lu is reasonably considered a process for preparing BHBT involving recycling a polyester.
Lu teaches the production mode of the production equipment for the disclosed process may be intermittent [n0014]. In such embodiments of Lu, the BHET would be fed in at least two portions. Lu additionally teaches that, in step (2), ethylene glycol as a byproduct is condensed as a gas phase and then enters an ethylene glycol collection tank for recycling [n0021], i.e. ethylene glycol as a byproduct is removed.
Lu further teaches the feeding of BHET is carried out a temperature in 225 to 245°C [n0021], which is outside the claimed range of 165 to 200°C. However, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.);
Lu additionally does not teach step (2) is carried out in a nitrogen atmosphere. However, Inada teaches the concept of providing a nitrogen atmosphere in a reactor in which a step corresponding to instantly claimed step (2) is performed [0034]. Lu and Inada are analogous are as they are from the same field of endeavor, namely methods of preparing BHBT and polybutylene terephthalate (PBT) from waste polyester. Before the effective filing date of the instantly claimed invention, it would have been obvious to a person of ordinary skill in the art to provide the reactor used in step (2) of Lu with a nitrogen atmosphere. The motivation would have been that a nitrogen atmosphere would create an inert environment, thereby minimizing impurities in the final product.
Finally, Lu does not expressly teach instantly claimed Relationship (1) is satisfied during the process. However, Inada teaches providing a molar ratio of BHET:BD equal to 1:3 [0034], which can alternatively be expressed according to Relationship (1) as a G/B molar ratio of 3. Before the effective filing date of the instantly claimed invention, it would have been obvious to a person of ordinary skill in the art to provide a molar ratio G/B of 3 in the process of Lu, a suggested by Inada. The motivation would have been that Lu teaches this is suitable ratio for the formation of BHBT which is subsequently used in a process of making PBT.
Regarding Claim 5. Lu teaches the process of Claim 4 but is silent regarding the purity of BHBT. Consequently, the Office recognizes that all of the claimed effects or physical properties are not positively stated by the reference(s). However, Lu, when modified with Inada in the manner proposed above, teaches a process employing all of the claimed steps and substantially similar processing conditions, as well as the claimed ingredients in the claimed amounts. Therefore, the claimed effects and physical properties, i.e. a BHBT having a purity in the instantly claimed range as determined by high pressure light chromatography, would implicitly be achieved by a process employing all of the claimed steps and substantially similar processing conditions, as well as the claimed ingredients in the claimed amounts. See In Re Spada, 911, F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990) and MPEP 2111.01 (I)(II). If it is applicant’s position that this would not be the case: (1) evidence would need to be provided to support the applicant’s position and (2) it would be the Office’s position that the application contains inadequate disclosure as to how to obtain the claimed properties using only the claimed process employing the claimed steps, processing conditions, and ingredients in the claimed amounts.
Regarding Claim 6. Lu teaches the process of Claim 4 wherein the BHET is obtained by alcoholyzing/depolymerizing waste PET/polyester [n0020].
Regarding Claim 9. Lu teaches the process of Claim 4 but is silent with respect to the molar content of ethylene glycol, diethylene glycol, and their derivatives in the obtained BHBT. However, Lu, when modified with Inada in the manner proposed above, teaches a process employing all of the claimed steps and substantially similar processing conditions, as well as the claimed ingredients in the claimed amounts. Therefore, the claimed effects and physical properties - i.e. a BHBT having a molar content of ethylene glycol, diethylene glycol, and their derivatives in the instantly claimed range - would implicitly be achieved by a process employing all of the claimed steps and substantially similar processing conditions, as well as the claimed ingredients in the claimed amounts. See In Re Spada, 911, F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990) and MPEP 2111.01 (I)(II). If it is applicant’s position that this would not be the case: (1) evidence would need to be provided to support the applicant’s position and (2) it would be the Office’s position that the application contains inadequate disclosure as to how to obtain the claimed properties using only the claimed process employing the claimed steps, processing conditions, and ingredients in the claimed amounts.
Regarding Claims 16 and 17. Lu teaches the process of Claim 4 involves obtaining bis(hydroxyethyl)terephthalate (BHET) from waste polyethylene terephthalate and then esterifying with BDO/1,4-butandiol [n0019] – [n0022]. Inada provides evidence that the reaction of BHET with BDO is a transesterification reaction which produces bis(4-hydroxybutyl)terephthalate (BHBT) [0008]. Thus, the intermediate product in Lu is reasonably expected to be BHBT.
Lu is silent with respect to the molar content of ethylene glycol, diethylene glycol, and their derivatives in the obtained BHBT, as well as the color-b value in a Hunter Lab color space of a specimen thereof having a thickness of 6 mm. However, Lu teaches a product prepared from all of the claimed ingredients in the claimed amounts by a substantially similar process. Therefore, the claimed effects and physical properties – i.e. a BHBT having the claimed properties – would implicitly be achieved in a product prepared from all of the claimed ingredients in the claimed amounts by a substantially similar process. See In Re Spada, 911, F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990) and MPEP 2111.01 (I)(II). If it is applicant’s position that this would not be the case: (1) evidence would need to be provided to support the applicant’s position and (2) it would be the Office’s position that the application contains inadequate disclosure as to how to obtain the claimed properties in a product prepared from all of the claimed ingredients in the claimed amounts by a substantially similar process.
Regarding Claim 18. Lu teaches the BHBT of Claim 16 may be pelletized [n0023] but does not expressly teach pelletizing to provide flakes weighing 0.2 grams or less at room temperature. However, the Federal Circuit has held that, where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device.
Regarding Claim 19. Lu teaches the BHBT of Claim 16 is used as an intermediate/ raw material for the production of a polyester resin, namely polybutylene terephthalate (PBT) [n0001], [0007], [0008], and [n0019] – [n0022].
Response to Arguments
Applicant's arguments filed March 26, 2026 have been fully considered but they are not persuasive.
Applicant argues that the applied prior does not teach (1) performing a transesterification reaction by feeding bis(2-hydroxyethyl)terephthalate (BHET) into a reactor in a divided or continuous matter; (2) a method satisfying Relationship (1); (3) that BHET is fed into two or more divided portions, where the feed ratio (R) according to specific Formula (2) is 5 or more; and (4) the feeding of BHET is carried out under a nitrogen atmosphere at a temperature of 165 to 200°C while removing ethylene glycol as a byproduct.
However, the Office maintains that all of the aforementioned limitations are met by the combination of Lu with Inada. With respect to (1), Lu teaches the production mode of the production equipment for the disclosed process may be intermittent [n0014]. In such embodiments of Lu, the BHET would be fed in a divided manner. With respect to (2), Inada teaches providing a molar ratio of BHET:BD equal to 1:3 [0034], which can alternatively be expressed according to Relationship (1) as a G/B molar ratio of 3. It is the Office’s position that, before the effective filing date of the instantly claimed invention, it would have been obvious to a person of ordinary skill in the art to provide a molar ratio G/B of 3 in the process of Lu, a suggested by Inada for the reasons detailed in the rejection of Claim 4 under 35 U.S.C. 103.
With respect to (3), it is the Office’s position that such a relationship would be satisfied when Lu and Inada are combined in the manner proposed. As detailed in the rejection of Claim 4 under 35 U.S.C. 103, it would have been obvious to a person of ordinary skill in the art to provide a molar ratio G/B of 3 in the process of intermittent process of Lu, a suggested by Inada. Additionally, the intermittent process embodiment disclosed by Lu would necessarily involve the introduction of BHET into the reactor in a divided manner of two or more times (N=2 or more); thus, utilizing the ratio of G/B of 3 in the intermittent process would also satisfy instantly claimed Relationship 2 by providing an introduction ratio (R) of 5 or more (G x N/B = G/B x N = 3 x 2+ = 5+).
With respect to (4), Lu teaches that, in step (2), ethylene glycol as a byproduct is condensed as a gas phase and then enters an ethylene glycol collection tank for recycling [n0021], i.e. ethylene glycol as a byproduct is removed. The Office does recognize that Lu teaches feeding of BHET is carried out a temperature in 225 to 245°C [n0021], which is outside the claimed range of 165 to 200°C. However, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. Additionally, it is the Office’s position that it would have been obvious to a person of ordinary skill in the art to provide the reactor used in step (2) of Lu with a nitrogen atmosphere for the reasons set forth in the outstanding and present rejections of Claim 4 under 35 U.S.C 103.
Applicant additionally argues that that the examples of the present application show that G/B of 2 or greater is a necessary condition for securing stable physical properties. Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980)
The Office respectfully submits that the examples provided by in the instant specification are not sufficient to establish criticality of the claimed range. Applicant cites Example 3 in which a G/B of 1.8 is provided and a BHBT content of 60.9% and an rBHBT Color-b value of 4.8 are obtained, which applicant characterizes as inferior to the other examples in the presently filed remarks. However, the instant specification characterizes the purity obtained in this example, i.e. the BHBT content, as “excellent”. The instant specification further describes the recycled BHBT to have “excellent color” (see [0138] of the PG-PUB of the instant application). It is noted that all of the comparative examples obtain significantly lower BHBT contents than Example 3 (ranging from 4.8 to 45.3 weight percent), as well as significantly higher rBHBT Color-b values (ranging from 8.8 to 10.5). On the other hand, the other inventive examples obtain BHBT contents and an rBHBT Color-b values which are substantially similar and much closer to those obtained in Example 3. This is evidenced by the fact that applicant groups the discussion of Example 1 – 6 together and characterizes the aforementioned properties of the obtained BHBT as excellent. Example 3 does not then demonstrate that the properties obtained with G/B ratio differ to such an extent that the difference is truly unexpected.
Applicant additionally argues that BHBT content is also significantly lower and the rBHBT color B value is high, when divided feeding is not employed and the reaction conditions do not fall within the scope of the claimed invention. Applicant cites Comparative Examples 4 and 5 in support of this position. However, the evidence provided must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979). The Office respectfully submits that Comparative Examples 4 and 5 are not representative of the closest prior art, as they provide only one feeding of rBHET. On the other hand, closest prior art Lu discloses an intermittent process from which two or more feedings of BHET would be readily envisioned.
The Office additionally submits that Comparative Examples 4 and 5 modify a number of variables simultaneously relative to the inventive examples, including the number of divided feedings of rBHET, G/B ratio, BD quantity, and reaction temperature. A person of ordinary skill in the art would not then be able to conclude which of these variable(s) is responsible for the inferior BHBT contents and rBHBT color b values observed.
For these reasons, the outstanding rejection under 35 U.S.C. 103 has been maintained.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Correspondence
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/MELISSA A RIOJA/Primary Examiner, Art Unit 1764
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