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 .
Claims 1-4 and 7-14 are pending as amended on December 10, 2025. Support for amended claim 1 is found on page 5, lines 11-13 of the instant specification. Claims 11-14 remain withdrawn from consideration.
The new grounds of rejection set forth below were necessitated by the amendment to claim 1 requiring that the modified polycarbonate has an increase in para-hydroxy phenol groups compared to the polycarbonate. Therefore, this action is properly made final.
Any objections and/or rejections made in the previous Office action and not repeated below are hereby withdrawn. The text of those sections of Title 35, U.S. Code not included in the action can be found in a prior Office action.
Response to Arguments
Applicant’s arguments filed December 10, 2025 have been fully considered.
Applicant’s arguments with respect to claims 1-4 and 7-10 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Kadoki (US 2013/0216801 A1) continues to be relied upon in the rejection of claim 2 and Monden (US 2011/0245388 A1) continues to be relied upon in the rejections of claims 3 and 8, but Applicant has not specifically challenged the teachings currently relied upon.
Claim Rejections - 35 USC § 103
Claims 1, 4, 7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Xu (CN-102241880-A, English translation provided) and evidenced by Ono (JP-2000086879-A, English translation provided).
Regarding claims 1 and 7, Xu teaches a method of preparing a composition consisting of polycarbonate, brominated triazine, diphenyl phosphate, an antioxidant, and stearamide (stearic acid amide reads on stearamide, page 3, lines 45-51). Stearamide (claim 7) is a primary amide of general structure R-CO-NH2 wherein R is a saturated aliphatic group having 17 carbon atoms. The composition is mixed and then placed in a twin-screw machine, melt extruded and cooled (page 3, lines 59-60). The twin-screw machine has eight temperature zones of which zone 1 is 210-220 °C, zones 2 and 5-6 are 220-230 °C and zones 3-4 and 7-8 are in the range of 230-250 °C (page 4, lines 1-3). The residence time is 1-2 minutes (page 4, line 3).
Xu does not anticipate a temperature of at least 230 °C for zones 2 and 5-6. However, it would have been obvious to one of ordinary skill in the art prior to the effective filing date to have selected any temperature in the range of 220-230 °C for the zones 2 and 5-6 because Xu teaches this range. A range of 220-230 °C overlaps with the claimed range of at least 230 °C. 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. Given that the overall residence time is 1-2 minutes and 7 of the 8 stages have a temperature of at least 230 °C, Xu teaches approximately 0.9-1.75 minutes at a temperature of at least 230 °C.
Xu does not explicitly teach that the polycarbonate and stearamide react to form a modified polycarbonate the claimed increase in melt volume rate and para-hydroxy phenol groups compared to the polycarbonate.
However, modified Xu teaches reaction conditions that would necessarily lead to the claimed reaction and increase in melt volume flow rate and para-hydroxy phenol groups. Modified Xu teaches that polycarbonate and stearamide are in contact at a temperature of at least 230°C for approximately 0.9-1.75 minutes. The instant specification specifies that a temperature of at least 230 °C and a time of at least 0.5 minutes is sufficient to form the modified polycarbonate (instant specification page 7, line 34 through page 3, line 1). Xu teaches using stearamide in an amount of 0.44 wt.% based on the amount of polycarbonate (Xu example 4 uses 0.2% stearamide and 45% polycarbonate, page 3, lines 45-51). This amide content is within the preferred range of 0.1-1.0 wt.% recited in the instant specification (instant specification, page 8, lines 11-14). Like the instant method, Xu’s composition does not include a solvent (Xu, page 3, lines 46-48; instant specification, page 8, lines 28-29). Given that the relative amounts of stearamide and polycarbonate, time, temperature, and lack of solvent taught by Xu are consistent with the conditions suggested by the instant specification as facilitating polycarbonate modification, it is reasonable to expect that the claimed reaction necessarily occurs and leads to the claimed increase in melt flow volume and para-hydroxy phenol groups.
Ono provides evidentiary support for this position. Ono teaches that when fatty acid amide-based internal mold release agents, including stearic acid amide, are blended with a polycarbonate resin, the polycarbonate resin is decomposed (Ono, [0033]). Ono demonstrates that stearamide is known to decompose polycarbonate when blended together. Decomposition is a reaction that necessarily modifies the polycarbonate to produce more chain ends, including para-hydroxy phenol groups. In addition, decomposition reduces molecular weight and one of ordinary skill would expect lower molecular weight to contribute to lower viscosity and higher melt flowrate.
Regarding claim 4, Xu teaches that the molecular weight of the polycarbonate is 20,000-30,000 g/mol (Xu, page 1, line 58) prior to modification. Xu is silent as to method of measuring the molecular weight; however, one of ordinary skill would be capable of selecting an appropriate standard and would therefore obtain a similar molecular weight. Xu’s molecular weight range is within the claimed range; however, as discussed above for claim 1, polycarbonate is known to decompose when mixed with stearamide, suggesting the molecular weight will decrease after modification.
Xu is silent as to the molecular weight of the modified polycarbonate.
However, Xu teaches a modified polycarbonate that is formed in a substantially similar manner as recited in the present claims and described in the instant specification. As discussed above, Xu uses solvent-free melt mixing to prepare the modified and teaches using stearamide in an amount of 0.44 wt.% based on the amount of polycarbonate, a temperature range of 230-250 °C and a time of approximately 0.9-1.75 minutes. In contrast, the instant examples use a temperature range of 250-300 °C (instant specification, page 10, lines 7-8) and does not specify the reaction time. Of the working examples, E3 is most similar to Xu because E3 uses 0.3 wt% of a saturated linear alkyl amide and a polycarbonate with a molecular weight within the range taught by Xu (instant Tables 1-2). Instant specification Table 2 shows that the weight average of the modified polycarbonate is about 7% lower than that of the starting polycarbonate. Because the modification method of Xu and the instant specification are substantially similar, one of ordinary skill in the art would expect the molecular weight of Xu’s modified polycarbonate to decrease by up to 7%. A 7% decrease leads to a molecular weight range of about 18,600 Daltons (20,000*0.93=18,600) to about 27,900 Daltons (30,000*0.93=27,900).
Regarding claim 9, Modified Xu teaches the method of claim 1. The method uses a twin-screw machine (twin screw machine, page 3, line 59), reading on wherein the method is a continuous method. Twin screw extruders enable continuous methods, as evidenced by the instant specification. Instant specification page 9, lines 2-3 read “The use of an extruder allows the modification to be carried out continuously thereby providing a polycarbonate with a stable level of modification.”
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Xu (CN-102241880-A, English translation provided) and evidenced by Ono (JP-2000086879-A, English translation provided) as applied to claim 1 above, and further in view of Kadoki (US 2013/0216801 A1, cited with 9/19/2025 Office action).
Modified Xu teaches the polycarbonate of claim 1. The industries taught by Xu include automotive, electronics, and computer industries (Xu, page 1, lines 20-25).
Xu is silent as to the transmission, haze, yellowness, and Izod impact strength of the polycarbonate.
However, Kadoki teaches polycarbonate compositions comprising fatty amides and flame retardants (Kadoki, [0055-0056]) used in articles for automotive parts and electronic applications (Kadoki, [0002]). Kadoki further teaches a light transmittance of at least 89% (Kadoki, [0083]) and a haze no greater than 1 (Kadoki, [0083]). It is noted that Kadoki teaches an article thickness of 0.2 mm to 3.0 mm (Kadoki, [0014]). A thickness of 0.2 mm is 3.0 mm is thinner than the claimed 3.2 mm plaque thickness. However, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to target the same properties as Kadoki, even for slightly thicker articles, in order to produce polycarbonate articles useful in electronic applications such as electronic device screens (Kadoki, [0002]).
It would have been obvious to one of ordinary skill in the art at the time of the invention to form a composition according to Xu having a transmission of at least 89% and a haze no greater than 1%, as Kadoki demonstrates this range as being suitable for similar compositions. This represents the use of a suitable ranges of transmission and haze in a similar electronics application. "The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416-21 (2007). See MPEP 2141.
Claims 3 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Xu (CN-102241880-A, English translation provided) and evidenced by Ono (JP-2000086879-A, English translation provided) as applied to claim 1 above, and further in view of Monden (US 2011/0245388 A1, cited with 9/19/2025 Office action).
Regarding claim 3, modified Xu teaches the method of claim 1. Xu teaches flame retardant polycarbonate compositions (Xu, title) and teaches that polycarbonates have excellent comprehensive performance with properties such as high impact resistance and high heat distortion temperature (Xu, page 1, lines 20-24). Xu highlights applications in the computer industry (Xu, page 1, lines 24-25). Xu refers only to polycarbonate and does not specify what monomers the polycarbonate is derived from.
However, Monden teaches flame-resistant polycarbonate resin compositions for use in computers (Monden, [0003]). Monden teaches that polycarbonates derived from bisphenol A are preferred in terms of impact resistance and heat resistance (Monden, [0192]). Such polycarbonates can be obtained from an interfacial process comprising reacting bisphenol A with phosgene (Monden, [0247] where the dihydroxy compound is bisphenol A) or by a direct transesterification process comprising reacting bisphenol A with diphenyl carbonate in molten state (Monden, [0257] and [0259] where the dihydroxy compound is bisphenol A).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date to have prepared the composition of Xu using the bisphenol A polycarbonate of Monden in order to utilize a polycarbonate with good impact resistance and heat resistance that is known to be suitable for the computer industry.
Regarding claim 8, Modified Xu teaches the method of claim 1.
Xu does not teach post-consumer recycled polycarbonate.
However, prior to the effective filing date, mixtures of virgin polycarbonate and post-consumer recycled polycarbonate were known as alternatives to virgin polycarbonate, as taught by Monden. Monden teaches that polycarbonate resin may be not only made of virgin raw materials but also a polycarbonate resin generated from used products, such as optical recording media, light guide plates, and vehicle transparent members (Monden, [0275]), reading on post-consumer recycled polycarbonate. Monden further teaches that the amount of regenerated polycarbonate resin is preferably 80% by mass or less because regenerated polycarbonate resins are likely to have undergone degradation (Monden, [0276]).
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). 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 substituted up to 80% by mass of the polycarbonate of Xu with post-consumer recycled polycarbonate, as taught by Monden. One would have had a reasonable expectation of successfully producing a polycarbonate article with typical optical and mechanical properties because a polycarbonate composition comprising up to 80% by mass of post-consumer recycled polycarbonate is below the concentration of post-consumer recycled polycarbonate that can cause deterioration in hue and mechanical properties (Monden, [0276]).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Xu (CN-102241880-A, English translation provided) and evidenced by Ono (JP-2000086879-A, English translation provided) as applied to claim 1 above, and further in view of Wasmuht (CA-2766835-A1).
Modified Xu teaches the method of claim 1 where the resin is processed with a twin-screw machine and melt-extruded (Xu, page 3, line 59).
Xu does not explicitly teach that the extruder has a die that produces at least one strand. However, one of ordinary skill in the art would know that extruders are equipped with a die and expect any die to produce at least one strand.
Xu further teaches cooling (Xu, page 3, lines 59-60) and granulating (Xu, page 2, line 13) the resin, but does not provide a detailed description of if the resin is in the shape of a strand when cooled and how to granulate the resin. As a result, Xu does not explicitly teach cooling a strand and cutting a strand into pellets.
However, Wasmuht teaches a method for the production on a polymer granulate (Wasmuht, abstract). Wasmuht’s method comprises continuously production a polymer strand from a polymer melt and cutting the resultant polymer strand into a polymer granule (Wasmuht, abstract). The method preferably comprises a step of cooling the polymer strand that is carried out at least partially between the step of producing the polymer strand and the cutting step (Wasmuht, page 4, paragraph 5).
It would have been obvious to one of ordinary skill in the art prior to the effective filing date to have substituted the granulation method of Xu for that of Wasmuht. One would have been motivated to make this substitution in order to prevent agglomeration of the polymer pellets and use an efficient and inexpensive procedure (Wasmuht, page 2, paragraph 3). Including the cooling and cutting steps of Wasmuht results in a method comprising cooling the strand and cutting the strand into pellets.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/AUDRA J DESTEFANO/Examiner, Art Unit 1766
/RANDY P GULAKOWSKI/Supervisory Patent Examiner, Art Unit 1766