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 .
Election/Restrictions
Restriction to one of the following inventions is required under 35 U.S.C. 121:
I. Claims 1-9, drawn to a method, classified in C08G63/78.
II. Claim 10, drawn to a copolyester, classified in C08G63/06.
The inventions are independent or distinct, each from the other because:
Inventions I and II are related as process of making and product made. The inventions are distinct if either or both of the following can be shown: (1) that the process as claimed can be used to make another and materially different product or (2) that the product as claimed can be made by another and materially different process (MPEP § 806.05(f)). In the instant case the product as claimed could be made by adding the talcum powder at a different point in the process, such as after the transesterification, after the prepolymerization, or after the polycondensation reaction. The product as claimed could also be made by adding the crystallization accelerator at a different point in the process, such as after the transesterification.
Restriction for examination purposes as indicated is proper because all the inventions listed in this action are independent or distinct for the reasons given above and there would be a serious search and/or examination burden if restriction were not required because one or more of the following reasons apply:
the inventions have acquired a separate status in the art in view of their different classification.
During a telephone conversation with Belinda Lee on 9/17/2025 a provisional election was made with traverse to prosecute the invention of Group I, claims 1-9. Affirmation of this election must be made by applicant in replying to this Office action. Claim 10 is withdrawn from further consideration by the examiner, 37 CFR 1.142(b), as being drawn to a non-elected invention.
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
The examiner has required restriction between product or apparatus claims and process claims. Where applicant elects claims directed to the product/apparatus, and all product/apparatus claims are subsequently found allowable, withdrawn process claims that include all the limitations of the allowable product/apparatus claims should be considered for rejoinder. All claims directed to a nonelected process invention must include all the limitations of an allowable product/apparatus claim for that process invention to be rejoined.
In the event of rejoinder, the requirement for restriction between the product/apparatus claims and the rejoined process claims will be withdrawn, and the rejoined process claims will be fully examined for patentability in accordance with 37 CFR 1.104. Thus, to be allowable, the rejoined claims must meet all criteria for patentability including the requirements of 35 U.S.C. 101, 102, 103 and 112. Until all claims to the elected product/apparatus are found allowable, an otherwise proper restriction requirement between product/apparatus claims and process claims may be maintained. Withdrawn process claims that are not commensurate in scope with an allowable product/apparatus claim will not be rejoined. See MPEP § 821.04. Additionally, in order for rejoinder to occur, applicant is advised that the process claims should be amended during prosecution to require the limitations of the product/apparatus claims. Failure to do so may result in no rejoinder. Further, note that the prohibition against double patenting rejections of 35 U.S.C. 121 does not apply where the restriction requirement is withdrawn by the examiner before the patent issues. See MPEP § 804.01.
Claim Interpretation
Claims 4, 6, and 8 include the phrase “based on a total weight of the bis-2-hydroxylethyl terephthalate.” This is interpreted as the weight of the bis-2-hydroxylethyl terephthalate present after the transesterification step and before the prepolymerization reaction.
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 1-2, 5, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Liu (CN-104031252-A, Cite No. 1 on 9/14/2023 IDS, English translation provided) in view of Rieckmann (Modern polyesters: chemistry and technology of polyesters and copolyesters, Chapter 2. Poly(ethylene terephthalate) polymerization – mechanism, catalysis, kinetics, mass transfer and reactor design, John Wiley & Sons, Ltd., 2003, 31-115) and Idokawa (JP-2009191158-A, English translation provided).
Regarding claims 1 and 5, Liu teaches a manufacturing method of a polyethylene terephthalate (PET) copolyester (Liu, [3]). Liu teaches putting terephthalic acid (TA) and ethylene glycol (EG) into a beating kettle, adding a nucleating agent together for beating and putting it into a slurry supply tank (Liu, [17]), resulting in a slurry that then undergoes an esterification reaction (Liu, [18]). A preferred nucleating agent taught by Liu is talc powder (Liu, [27]). Polyethylene glycol (PEG) is added between the esterification reaction (PEG… added online through the syringe 1, Liu, [19]) and subsequent pre-polycondensation and final polycondensation steps (Liu, [22]).
While Liu does not explicitly teach that the esterification reaction produces bis-2- hydroxyethyl terephthalate (BHET), one of ordinary skill would recognize that the esterification reaction of EG and TA produces BHET and short-chain oligomers, as evidenced by Rieckmann (page 35, paragraph 1). It is therefore reasonable to expect BHET formation during the esterification step. It is noted that while claim 1 claims a transesterification step between TA and EG to produce BHET, an esterification between TA and EG reads on the instantly claimed transesterification step because the reaction between TA and EG to form BHET is typically referred to as an esterification reaction. In the context of BHET production, transesterification typically refers to a reaction between an ester derivative of TA (e.g., dimethyl terephthalate) and EG, converting one ester to another ester. See page Rieckmann, page 35, paragraphs 1-2 for esterification/transesterification terminology in the context of BHET production.
Liu differs from instant claim 1 in that talcum powder is added to a mixture of TA and EG to form a slurry rather than adding a slurry comprising talcum powder to a mixture of TA and EG and in that Liu teaches that the esterification reaction occurs prior to adding the crystallization accelerator (PEG) rather than in the presence of the crystallization accelerator. Case law has established that selection of any order of performing process steps is prima facia obvious in the absence of new or unexpected results (see MPEP § 2144.04, IV. C.).
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have formed a mixture of TA, EG and talcum powder, as taught by Liu, by mixing Liu's three disclosed components together utilizing any order of addition, including first mixing the EG and the talcum powder (corresponding to the presently recited step of preparing a dispersion slurry), and then adding the TA to the mixture of EG and talcum powder (corresponding to the presently recited steps of mixing TA and EG, and introducing a dispersion slurry). One would have had a reasonable expectation of success in utilizing any order of mixing because the same desired combination of the components is ultimately obtained, and there is nothing of record to suggest that the order of mixing is critical to the method of manufacturing PET.
It would have further been obvious to one of ordinary skill in the art prior to the effective filing date to have added PEG at any point in the process so long as it was present in the pre-polycondensation kettle and final polycondensation kettle, as taught by Liu, including adding the PEG prior to the esterification reaction. One would have had a reasonable expectation of success in adding the PEG prior to the esterification reaction because it is ultimately present in the subsequent pre-polycondensation reaction and there is nothing of record to suggest that adding the PEG after the esterification reaction is critical to the method of manufacturing PET.
Liu therefore teaches a manufacturing method of a PET copolyester, comprising: preparing a dispersion slurry, wherein the dispersion slurry comprises a talcum powder (talc powder); mixing a TA and an EG, and introducing the dispersion slurry and a crystallization accelerator (PEG, reads on claim 5), so as to carry out a transesterification (esterification) and therefore form a BHET; and carrying out a prepolymerization reaction (pre-polycondensation) and a polycondensation reaction (final polycondensation), so that the BHET forms a PET copolyester.
Liu teaches that the talcum powder has a size of 4000-10000 mesh (Liu, [27]). A range of 4000-10000 mesh corresponds a particle size range of approximately 1 µm to 3 µm, falling within the claimed range of 1 µm to 50 µm. Liu is silent as to the specific surface area of the talc powder.
However, Idokawa teaches polyester resins (Idokawa, title) comprising talc nucleating agent particles with an average particle size of 3 µm or less and a specific surface area of 15 m2/g or more (Idokawa,[0038]). Idokawa further teaches that when this average particle size or specific surface area is not satisfied, the function as a crystal nucleus is poor (Idokawa, [0038]). Both Idokawa and Liu teach talc powders with particle sizes in the range of 1 µm to 3 µm (3 µm or less for Idokawa) used as nucleating agents in polyester resins.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have selected talc powder with the specific surface area of 15 m2/g or more taught as by Idokawa in order to utilize a talc powder with a specific surface area appropriate for the powder to function as a crystal nucleus. A range of 15 m2/g or more overlaps with the claimed range of 7 m2/g to 20 m2/g. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 2, modified Liu teaches the manufacturing method of claim 1. Liu further teaches that the amount of the talcum powder (nucleating agent) is 0.2-0.6% of the total mass of the TA and the EG (Liu, [17]).
As discussed in claim 1 above, Liu was modified such that the talcum powder is added to EG to form a slurry. The concentration of talcum powder in the slurry can be calculated using the amount of EG and talcum powder taught by Liu. Liu teaches a preferred molar ratio of TA to EG of 1:1.15 (Liu, [27]). TA has a molecular weight of 166 g/mol and EG has a molecular weight of 62 g/mol. Using a 1 mole basis of TA, Liu teaches a total amount of 166 g of TA and 71.3 g of EG (62*1.15=73.2), corresponding to about 0.5-1.4 g of talcum powder (0.2% to 0.6% of (166+71.3) = 0.5 to 1.4). A slurry consisting of 0.5-1.4 g of talcum powder and 71.3 g of EG corresponds to a range of 0.7-2 wt% (0.5/71.3=0.007 and 1.4/71.3=0.02). A range of 0.7-2 wt% talcum powder in the slurry overlaps with the claimed range of wherein based on a total weight of the dispersion slurry, a content of the talcum powder ranges from 0.5 wt% to 1.0 wt%. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 9, modified Liu teaches the manufacturing method of claim 1. Liu teaches that the reaction mixture enters the pre-polycondensation kettle and the final polycondensation kettle in sequence (Liu, [22]), reading on wherein the polycondensation reaction is carried out after the prepolymerization reaction. Liu further teaches a reaction temperature of 275-285 °C (Liu, [26]) and a pressure of 100-250 Pa (Liu, [25]) in the final polycondensation vessel. Liu therefore teaches during the polycondensation reaction, a reaction temperature ranges from 275 °C to 285 °C and a vacuum degree ranges from 0.75 mmHg to 1.87 mmHg. A range of 0.75-1.87 mmHg overlaps with the claimed range of 1-2 mmHg. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Liu does not specify a reaction time. Because Liu teaches reaction conditions, but is silent as to the reaction time, one would have been motivated to look to typical polycondensation reaction times used for PET synthesis under similar reaction conditions.
Prior to the effective filing date of the claimed invention, a reaction time of 90-150 minutes was known to be typical for the final polycondensation of PET in continuous processes with a temperature range of 275-295 °C and a pressure range of 50-150 Pa (Rieckmann, page 98, Table 2.13). The temperature range of Liu falls within that of Rieckmann and the pressure range of Liu overlaps with that of Rieckmann. Given the disclosure of Rieckmann, one of ordinary skill would expect a reaction time of 90-150 minutes to be suitable for the process of Liu.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have combined the polycondensation conditions of Liu with the reaction time of Rieckmann in order to obtain the PET of Liu. One would have been motivated to make this combination because Liu teaches a polycondensation reaction without specifying the reaction time, so utilizing a typical reaction time under the conditions of Liu would increase the likelihood of successfully producing PET. A reaction time of 1.5-2.5 hours overlaps with the claimed range of from 2 hours to 4 hours. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Claims 4 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Liu (CN-104031252-A) in view of Rieckmann (Modern polyesters: chemistry and technology of polyesters and copolyesters, Chapter 2. Poly(ethylene terephthalate) polymerization – mechanism, catalysis, kinetics, mass transfer and reactor design, John Wiley & Sons, Ltd., 2003, 31-115) and Idokawa (JP-2009191158-A) as applied to claim 1 above, and further in view of Ekart (US 2007/0270533 A1).
Regarding claim 4, modified Liu teaches the manufacturing method of claim 1 wherein the dispersion slurry comprises EG and talcum powder.
The mass of the EG plus the mass of the talcum powder reads on the added amount of the dispersion slurry. Liu teaches a preferable amount of talcum powder in the range of 0.2-0.6% based on the total mass of TA and EG (Liu, [17]) and a preferred molar ratio of TA to EG of 1:1.15 (Liu, [27]). Using a 1 mole basis of TA, Liu teaches a total amount of 166 g of TA and 71.3 g of EG (62*1.15=73.2), corresponding to about 0.5-1.4 g of talcum powder (0.2% to 0.6% of (166+71.3) = 0.5 to 1.4). Using a basis of 1 mole of TA, the mass of the dispersion slurry (EG and talcum powder) is 71.8-72.7 g.
Liu does not explicitly state how much BHET is formed during the esterification step. However, given that Liu teaches a preferred molar ratio of TA to EG of 1:1.15 (Liu, [27]) and each BHET molecule requires 2 EG molecules and 1 TA molecule, the maximum amount of BHET formed by Liu corresponds to about 70 wt% of the initial EG and TA (1.15 moles of EG + 1.15/2 moles of TA = 71.3 g + 95.5 g = 167 g and a starting mixture of 1.15 moles of EG and 1 mole of TA = 237 g).
While the maximum amount of BHET present after the esterification reaction corresponds to about 70 wt% of the initial EG and TA, the actual amount of BHET is likely lower, as evidenced by Ekart. Ekart teaches a continuous process for the manufacture of a polyester polymers (Ekart, [0064]), such as PET where in addition to EG the diol component may have additional aliphatic diols (Ekart, [0061]). Ekart further teaches that the products resulting from the esterification zone include BHET, low molecular weight oligomers, diethylene glycol, and water (Ekart, [0063]). For the products of a direct esterification process, Ekart teaches that the amount of oligomeric species is significant and that oligomeric species can even be the major species formed (Ekart, [0063]). Based on the disclosure of Ekart, one of ordinary skill would expect some amount of a low molecular weight oligomer to be produced during the esterification step, reducing the amount of BHET produced by the esterification reaction.
Because Ekart teaches that the amount of oligomeric species is significant and that oligomeric species can even be the major species formed (Ekart, [0063]) and the stoichiometry of EG and TA taught by Liu makes full conversion of EG and TA to BHET impossible, the mass of BHET is estimated as approximately up to 70 wt% of the initial EG and TA present in the esterification reaction. This range corresponds to a range of up to about 167 g BHET on a 1 mole of TA basis.
Using the same basis, the dispersion weights about 71.8-72.7 g, so the added amount of the slurry is 43 wt% or higher based on a total weight of the BHET. This overlaps with an added amount of the dispersion slurry ranges from 98.0 wt% to 99.0 wt%. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 8, modified Liu teaches the manufacturing method of claim 1 where the esterification produces BHET and the esterification is followed by a prepolymerization step in which PEG is present, as discussed above for claim 1, reading on wherein during the prepolymerization reactants include BHET and PEG.
Liu teaches that PEG is added in a range of 5-10% based on the total mass of TA and EG (Liu, [19]). Liu teaches a preferred molar ratio of TA to EG of 1:1.15 (Liu, [27]), so using a 1 mole basis of TA, Liu teaches a total amount of TA and EG of about 239 g. This corresponds to about 12-24 g of PEG.
Liu differs from instant claim 8 in that the quantity of PEG is based on the total amount of TA and EG rather than the amount of BHET. The quantity of PEG relative to BHET is estimated below.
As discussed above for claim 4, Liu does not explicitly state how much BHET is formed by the TA and EG during the esterification step. However, because Ekart teaches that the amount of the oligomeric species is significant and even the major species (Ekart, [0063]) and the stoichiometry of EG and TA taught by Liu makes full conversion of EG and TA to BHET impossible, the mass of BHET is estimated as approximately up to 70 wt% of the initial EG and TA present in the esterification reaction. This means that the upper limit of the mass of BHET produced is approximately 167 g (239*0.7) and, therefore, PEG is estimated to be present in an amount of at least 7 wt% (12 is 7% of 167) based on a total amount of BHET.
A range of at least 7 wt% overlaps with the claimed range of, wherein based on a total weight of the BHET, a content of the PEG ranges from 4 wt% to 8 wt%. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Liu teaches a preferred precondensation kettle pressure of 2500-3000 Pa (about 19-23 mmHg and temperature of 270-275 °C, but does not teach a specific reaction time (Liu, [24]). These temperature and pressures are higher than the claimed reaction temperature range of 250 °C to 260 °C and vacuum degree of 40 mmHg.
However, prior to the effective filing date, the claimed reaction conditions were known as alternatives to those used by Liu, as evidenced by Ekart. Ekart teaches a continuous process for the manufacture of a polyester polymers (Ekart, [0064]), such as PET where in addition to EG the diol component may have additional aliphatic diols (Ekart, [0061]). Ekart teaches a prepolymer polycondensation stage with a pressure range of 5-70 torr (5-70 mmHg), a temperature range of 250-305 °C, and a reaction time of 5 minutes to 4 hours (Ekart, [0067]). These pressure and temperature ranges encompass those taught by Liu and those of the claimed invention.
Given the disclosure of Ekart, one of ordinary skill in the art would have understood that a range of reaction pressures, temperatures, and times are appropriate for prepolymer polycondensation.
Case law has established that it is prima facie obvious to substitute one known element for another to obtain predictable results. KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007). MPEP § 2143, rationale (B). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have substituted the prepolymer polycondensation pressure, temperature, and unspecified reaction time of Liu for those taught by Ekart. One would have had a reasonable expectation of successfully producing the copolyester of Liu because the ranges of Liu fall within those taught by Ekart and Ekart also teaches the synthesis of PET copolyesters.
A pressure range of 5-70 mmHg, a temperature range of 250-305 °C, and a reaction time of 5 minutes to 4 hours overlap with the claimed reaction temperature range of 250 °C to 260 °C, a vacuum degree of 40 mmHg, and reaction time range of 1 hour to 2 hours. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Liu (CN-104031252-A) in view of Rieckmann (Modern polyesters: chemistry and technology of polyesters and copolyesters, Chapter 2. Poly(ethylene terephthalate) polymerization – mechanism, catalysis, kinetics, mass transfer and reactor design, John Wiley & Sons, Ltd., 2003, 31-115) and Idokawa (JP-2009191158-A) as applied to claim 1 above, and further in view of Ozawa (JP-2020084151-A, English translation provided).
Regarding claim 7, modified Liu teaches the manufacturing method of claim 1. Liu teaches a preferred molar ratio 1:1.15 (Liu, [27]). This preferred ratio is outside of the claimed range of 1:1.3 to 1:1.5.
However, prior to the effective filing date, the molar ratio of TA to EG was known in the art as a result effective variable, as evidenced by Ozawa.
Ozawa teaches a method for producing a polyester resin (Ozawa, [0053] where the polyester resin is derived from monomers comprising TA and EG (Ozawa, [0023] and [0025]). Ozawa teaches that the molar ratio of the diol component to the dicarboxylic acid component subjected to the esterification or transesterification reaction is usually in the range of 1.03 to 1.7 (Ozawa, [0030]). Ozawa teaches that when the molar ratio is less than the lower limit, the polycondensation reaction rate tends to decrease and when the molar ratio exceeds the upper limit, the amount of diethylene glycol produced increases and the thermal stability and mechanical strength of the resulting polyester resin may decrease (Ozawa, [0030]).
Based on the disclosure of Ozawa, one of ordinary skill in the art would have recognized that increasing the EG to TA ratio increases the amount of diethylene glycol produced and decreases the thermal stability and mechanical strength of the resin, while decreasing the EG to TA ratio decreases the reaction rate. Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have optimized the TA to EG ratio into the claimed range of 1:1.3 to 1:1.5. One would have been motivated to optimize the TA to EG ratio in order to balance the reaction rate, amount of diethylene glycol produced, and thermal and mechanical stability of the resin. The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
Liu teaches a preferred esterification temperature range of 255-258 °C, falling within the claimed range of 250 °C to 260 °C. Liu does not teach a reaction time.
Because Liu teaches reaction conditions, but is silent as to the reaction time, one would have been motivated to look to typical esterification reaction times used for PET synthesis under similar reaction conditions.
Prior to the effective filing date of the claimed invention, a reaction time of 180-360 minutes was known to be typical for the esterification stage of PET production in continuous processes with a temperature range of 250-265 °C, as evidenced by Rieckmann. The temperature range of Liu falls within that of Rieckmann. Given the disclosure of Rieckmann, one of ordinary skill would expect a reaction time of 180-360 minutes to be suitable for the esterification step of Liu.
Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have combined the esterification reaction conditions of Liu with the reaction time of Rieckmann in order to obtain the PET of Liu. One would have been motivated to make this combination because Liu teaches an esterification reaction without specifying the reaction time, so utilizing a typical reaction time under the conditions of Liu would increase the likelihood of successfully producing the PET of Liu. A reaction time of 1.5-3 hours overlaps with the claimed range of from 2 hours to 3 hours. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Allowable Subject Matter
Claims 3 and 6 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The closest prior art of record to claim 3 is Liu (CN-104031252-A) in view of Rieckmann (Modern polyesters: chemistry and technology of polyesters and copolyesters, Chapter 2. Poly(ethylene terephthalate) polymerization – mechanism, catalysis, kinetics, mass transfer and reactor design, John Wiley & Sons, Ltd., 2003, 31-115) and Idokawa (JP-2009191158-A), and Chen (CN-115260465-A, Cite No. 1 on 5/23/2024 IDS, English translation provided).
Liu in view of Rieckmann and Idokawa teaches the manufacturing method of claim 1, as discussed above, wherein the dispersion slurry comprises EG, as laid out above. Liu in view of Rieckmann and Idokawa does not teach or suggest wherein the dispersion comprises 0.01 wt% to 1 wt% of a dispersant.
Chen teaches a rapid crystallization polyester chip, with improved dispersibility of a nucleating agent in PET (Chen, [12]). The method of Chen includes combining an inorganic nucleating agent in EG (Chen, [15]), then adding a coupling agent hydrolyzed dispersion to the nucleating agent/EG dispersion (Chen, [16-17]) to obtain a surface modified inorganic nano-nucleating agent-EG dispersion (Chen, [18]). This dispersion is then reacted with TA and EG to prepare fast crystallizing polyester chips (Chen, [19]). Chen teaches that modification of the inorganic nucleating agent avoids agglomeration during the in-situ polymerization process and that the polyester and the nucleating agent are chemically bonded through the surface modifier (Chen, 24]). The coupling agent of Chen reads on a dispersing agent because it aids in avoiding nucleation agent agglomeration. As a nucleating agent, Chen teaches nano-montmorillonite, nano-barium sulfate, nano-calcium carbonate, and nano-hydrotalcite (Chen, [19]).
While Chen teaches use of a dispersing agent in nucleating agent slurry to reduce aggregation in PET synthesis, Chen cannot be combined with the method of Liu in view of Rieckmann and Idokawa because the nucleating agents taught by Chen do not include talcum powder. Claim 3 is therefore allowable.
The closest prior art of record to claim 6 is Liu (CN-104031252-A) in view of Rieckmann (Modern polyesters: chemistry and technology of polyesters and copolyesters, Chapter 2. Poly(ethylene terephthalate) polymerization – mechanism, catalysis, kinetics, mass transfer and reactor design, John Wiley & Sons, Ltd., 2003, 31-115), Idokawa (JP-2009191158-A), and Ekart (US 2007/0270533 A1).
Liu in view of Rieckmann and Idokawa teaches the manufacturing method of claim 1, as discussed above. Liu further teaches that PEG (reading on crystallization accelerator) is added in a range of 5-10% based on the total mass of TA and EG (Liu, [19]). Liu teaches a preferred molar ratio of TA to EG of 1:1.15 (Liu, [27]). Using a 1 mole basis of TA, Liu teaches a total amount of TA and EG of about 239 g. This corresponds to about 12-24 g of PEG.
Liu differs from instant claim 6 in that the quantity of PEG is based on the total amount of TA and EG rather than the amount of BHET. Liu teaches a preferred molar ratio of TA to EG of 1:1.15 (Liu, [27]). Each BHET molecule requires 2 EG molecules and 1 TA molecule, so the maximum amount of BHET formed by Liu corresponds to about 70 wt% of the initial EG and TA (see claim 4 discussion for math). In addition, Rieckmann and Ekart teach that esterification produces oligomers and BHET (Rieckmann, page 35, paragraph 1; Ekart, [0063]). Ekart teaches that the amount of oligomeric species is significant and oligomers can be the major species produced (Ekart, [0063]). This means that the upper limit of the mass of BHET produced is approximately 167 g (70% of 239) and, therefore, PEG is estimated to be present in an amount of at least 7 wt% (12 is 7% of 167) based on a total amount of BHET.
A range of at least 7 wt% is higher than the claimed range of wherein, based on a total weight of the BHET, an added amount of the crystallization accelerator ranges from 1 wt% to 5 wt%. Because Liu teaches a higher crystallization accelerator concentration above the claimed range and provides no teaching or suggestion to decrease the quantity of the crystallization accelerator, claim 6 is allowable.
Conclusion
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/AUDRA J DESTEFANO/Examiner, Art Unit 1766
/RANDY P GULAKOWSKI/Supervisory Patent Examiner, Art Unit 1766