DETAILED ACTION
This office action follows a reply filed on March 31, 2026. Claims 1, 3, 5-7 and 9 have been amended. Claims 1-15 are currently pending and under examination.
The texts of those sections of Title 35 U.S. Code are not included in this section and can be found in a prior Office action.
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
Claims 1-15 are rejected under 35 U.S.C. 103 as being unpatentable over Li (US 2013/0317146) in view of Xu (US 9,228,067) and further in view of WO 2019/123029, as evidenced by Zhao (US 9,023,922).
Li teaches a flame retardant polycarbonate composition with a transmissivity in a visible wavelength of greater than 80% at a thickness of 0.1-3 mm (p. 22, [0156], [0158] and claims 2-3) comprising the following:
10-90 wt% of a polycarbonate, which can be branched and is exemplified as a THPE branched polycarbonate;
10-70 wt% of a polysiloxane-polycarbonate copolymer; and
1-20 wt% of a phosphazene compound, which meets applicants’ flame retardant comprising a phosphorus-nitrogen bond.
Li teaches the polycarbonate as having at least 3 mol% branching moieties; however, Li does not specifically teach the combination of the claimed highly branched polycarbonate and the branched polycarbonate.
Xu teaches a flame-resistant polycarbonate film comprising a first and second branched polycarbonate, where the first polycarbonate comprises a branching agent and an end capping agent, and a second polycarbonate comprising a branching agent. Xu further teaches that a polysiloxane-polycarbonate copolymer can be added to improve the flame retardance (col. 20, l. 54).
Xu exemplifies the first polycarbonate as containing 3 mol% THPE branching agent and the second polycarbonate is exemplified as containing 0.0045 moles of branching agent per mol of BPA, where the molecular weight of each of the first and second branched polycarbonates is about 30,000 g/mol, suggesting a branching content in the second branched polycarbonate as about 0.4 mol% of the polycarbonate, as a BPA polycarbonate with low branching contains about 90% BPA. Xu specifically teaches that the quantity of branching units per 100 R1 units in the first polycarbonate can be 0.3-0.5 units higher than the quantity of branching in the second polycarbonate (col. 10, l. 66 to col. 11, l. 6).
Xu teaches that by balancing the molecular weight, branching level and end-group type, transparent polycarbonate formulations can be obtained that are easily molded into thin wall articles and pass UL94 testing (col. 12, ll. 54-62).
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have used a combination of a first and second branched polycarbonate with differing branching levels, as Xu teaches that the combination of such can provide transparent polycarbonate formulations which can be formed into thin walled articles with flame retardance.
Li teaches the polysiloxane polycarbonate as comprising up to 50 wt% of polysiloxane based on the total amount of the copolymer (p. 10, [0076]), but Li does not specifically teach the combination of a polysiloxane polycarbonate with a high polysiloxane content and a polysiloxane polycarbonate with a low polysiloxane content, as claimed.
WO ‘029 teaches a polycarbonate composition comprising 10-99 wt% of a polycarbonate homopolymer, which includes branched polycarbonates (p. 3, [0010]), a first poly(carbonate-siloxane) having a siloxane content of 30-70 wt% having a molecular weight of 30,000-45,000 g/mol, most preferably in an amount of 2-5 wt% (p. 8, [0027]-[0029]), and a second poly(carbonate-siloxane) having a siloxane content of 5-25 wt% most preferably in an amount of 10-25 wt% (p. 9, [0030]), where the composition has a total siloxane content of most preferably up to 4 wt% (p. 9, [0032]). WO ‘029 teaches that phenoxyphosphazene flame retardants can be added (p. 17, [0060]). WO ‘029 teaches that where a transparent poly(carbonate-siloxane) is desired, the siloxane blocks are unsubstituted by halogen (p. 6, [0018]).
WO ‘029 shows that when a poly(carbonate-siloxane) with 20 wt% of siloxane is partially replaced with a poly(carbonate-siloxane) with 60 wt%, and the total siloxane content in the composition is maintained, the flame retardance properties are improved. Compare ExamplesCEx2a (UL94 V0/V1 rating) and Ex3a (UL94 V0 rating).
Therefore, choosing a blend of a first polysiloxane polycarbonate with a siloxane content of 30-70 wt% and a second polysiloxane polycarbonate having a siloxane content of 5-25 wt%, where the composition has a total siloxane content of up to 4 wt%, is prima facie obvious, as WO ‘029 teaches that the flame retardance is improved when using a combination of polysiloxane polycarbonate copolymers, as Li is clearly interested in improving the flame retardance of similar compositions.
As to the ratio of siloxane content of the first to second poly(carbonate siloxane), WO ‘029 teaches a first poly(carbonate siloxane) having a siloxane content of 30-70 wt% and a second poly(carbonate siloxane) having a siloxane content of 10-25 wt%. This suggests a ratio of about 7:1 or less, the range of which overlaps with the claimed range of 6.7:1, and it has been held that overlapping ranges are sufficient to establish prima facie obviousness. See MPEP 2144.05.
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to have selected from the overlapping portion of the range taught by the reference because overlapping ranges have been held to establish prima facie obviousness.
While Xu requires the presence of a perfluoroalkyl sulfonate salt, Li teaches that the polysiloxane-carbonate polymer and the branched polycarbonate demonstrate a synergistic effect with the phosphazene compounds when used in a flame retardant composition, and the polysiloxane-carbonate polymer in combination with a phosphazene can be used in place of the perfluoroalkyl sulfonate salt as a flame retardant. See Table 5, Examples #7 versus Example #9. Therefore, the presence of a perfluoroalkyl sulfonate salt is not required to meet the desired flame retardance.
Li in view of Xu and WO ‘029 suggests the claimed combination of components and is prima facie obvious over instant claim 1.
As to claim 2, Xu teaches that the thermoplastic composition can be essentially free of chlorine and bromine, which is defined as having a bromine and/or chlorine content of less than or equal to 100 ppm (col. 22, ll. 41-53). Fluorinated components are optional therefore, a total amount of halogens of 200 ppm or less is suggested by the teachings of Xu.
As to claim 3, Li teaches the compositions as having a flame retardancy of V-0 at a thickness of 0.8 mm or lower (p. 22, [0159]); and exemplifies an Izod impact strength determined according to ASTM D256 of 1020 J/m (Table 5, Example #9).
As to claims 4 and 11-12, Li in view of Xu and WO ‘029 suggests a composition comprising 10-90 wt% branched polycarbonate, most preferably 2-5 wt% of a first poly(carbonate-siloxane) having a siloxane content of 30-70 wt% and 10-25 wt% of a second poly(carbonate-siloxane) having a siloxane content of 5-25 wt%. Li exemplifies the inclusion of 6 wt% of SPB-100 with a phosphorus content of about 13.4%, suggesting the inclusion of about 0.8 wt% phosphorus. Li teaches that the phosphazene can be present in an amount of 2.5-10 wt%, suggesting the phosphorus content as about 0.3-1, the range of which overlaps with the claimed range of 0.6 wt% or less, and it has been held that overlapping ranges are sufficient to establish prima facie obviousness. See MPEP 2144.05.
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to have selected from the overlapping portion of the range taught by the reference because overlapping ranges have been held to establish prima facie obviousness.
Note that applicants’ auxiliary polycarbonate is optional.
As to claims 5-6, Li teaches the polycarbonate as having end-groups derived from an end-capping agent having a pKa of 8.3 and 11 and includes groups such as phenol substituted with cyano group, an olefinic group, a halogen, an ester group, or combination thereof (p. 8, [0064]).
As to claims 7-8, Li teaches that the phosphazene has the following structure (p. 11, [0086]):
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As to claims 9-11, Li teaches that the polycarbonate composition can include 20-60 wt% of a post-consumer recycle polycarbonate (p. 9, [0066]).
As to claims 13-15, Li, Xu and WO ‘029 each teach melt-mixing the components and forming a molded article by way of extrusion.
Response to Arguments
Applicant's arguments filed March 31, 2026 have been fully considered but they are not persuasive.
Applicants argue that Li’s teaching regarding transparency is not sufficient to motivate one to obtain the compositions as presently claimed, while Xu does not teach the combination of poly(carbonate siloxane) copolymers.
Li specifically teaches a composition comprising a linear polycarbonate, which meets applicants’ auxiliary polycarbonate, a branched polycarbonate, a polysiloxane-polycarbonate (6 wt% siloxane and MW=23,000 g/mol), and a phosphazene compound.
Li specifically shows that this combination provides a transparency of greater than 80%. Li specifically teaches that the phosphazene compound can be used in polycarbonates to produce optically transparent compounds (p. 15, [0128]). Li specifically teaches that polysiloxane-polycarbonate copolymer acts synergistically with the branched polycarbonate to produce transparent compositions (p. 15, [0129]).
Li allows for the inclusion of the claimed branched copolycarbonates and both of the poly(carbonate) siloxanes while still meeting the claimed transparency. Li teaches a combination of a first and second polycarbonate-polysiloxane copolymer can be used with the differing values of E, where E determines the amount of siloxane content, and the siloxane units are present in an amount of 1-50 wt%, where the copolymer is end capped with a cumylphenol.
WO ‘029 teaches a combination of a first poly(carbonate-siloxane) having a siloxane content of 30-70 wt% having a molecular weight of 30,000-45,000 g/mol, most preferably in an amount of 2-5 wt% (p. 8, [0027]-[0029]), and a second poly(carbonate-siloxane) having a siloxane content of 5-25 wt% (p. 9, [0030]), where the composition has a total siloxane content of most preferably up to 4 wt% (p. 9, [0032]). WO ‘029 teaches that where a transparent poly(carbonate-siloxane) is desired, the siloxane blocks are unsubstituted by halogen (p. 6, [0018]).
Both of these poly(carbonate-siloxanes) overlap with that taught by Li; therefore, choosing a first and second poly(carbonate-siloxane) with silocane contents suggested by Li would be expected to provide a transparent molded article.
Each of Li, Xu, and WO ‘029 desire transparency, therefore, one of ordinary skill in the art would expect the combination of components to still result in a transparent composition, as claimed.
Applicants argue unexpected results.
When looking to showings of results in order to overcome a rejection, the following must be considered:
Results must be Unexpected:
Unexpected properties must be more significant than expected properties to rebut a prima facie case of obviousness. In re Nolan 193 USPQ 641 CCPA 1977.
Obviousness does not require absolute predictability. In re Miegel USPQ 716.
Since unexpected results are by definition unpredictable, evidence presented in comparative showings must be clear and convincing. In re Lohr 137 USPQ 548.
In determining patentability, the weight of the actual evidence of unobviousness presented must be balanced against the weight of obviousness of record. In re Chupp, 2 USPQ 2d 1437; In re March 175 USPQ; In re Battle, 24 USPQ 2d 1040.
Claims Must be Commensurate with Showings:
Evidence of superiority must pertain to the full extent of the subject matter being claimed. In re Ackerman, 170 USPQ 340; In re Chupp, 2 USPQ 2d 1437; In re Murch 175 USPQ 89: Ex Parte A, 17 USPQ 2d 1719; accordingly, it has been held that to overcome a reasonable case of prima facie obviousness a given claim must be commensurate in scope with any showing of unexpected results. In re Greenfield, 197 USPQ 227. Further, a limited showing of criticality is insufficient to support a broadly claimed range. In re Lemin, 161 USPQ 288.
Result Must Compare to Closest Prior Art:
Where a definite comparative standard may be used, the comparison must relate to the prior art embodiment relied upon and not other prior art - Blanchard v. Ooms, 68 USPQ 314 - and must be with a disclosure identical (not similar) with that of said embodiment: In re Tatincloux, 108 USPQ 125.
Applicants transparency may be unexpected, but the showing is not commensurate in scope with the claimed invention.
In Tables 7-9, the transparency is measured on a 3.2 mm thick disk, whereas the claimed invention requires a transparency of at least 80% on a 0.8 mm thick molded sample.
In Tables 10-11 show the claimed transparency; however, Table 10 does not have any Comparative Examples where the components are outside of the claimed invention and Table 11 requires the inclusion of PCR-polycarbonate, which is not required by the claimed invention.
Additionally, applicants have only shown the effects of a combination of a PC-Si-6 in combination with a PC-Si-40, where the claimed invention allows for any PC-Si of 5-15 wt% Si in combination with a PC-Si of 30-70 wt% Si.
Even further, all compositions include about 44 wt% of a PC-2, a linear BPA polycarbonate, which is not required by the claimed invention.
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.
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/Brieann R Johnston/Primary Examiner, Art Unit 1766
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