Prosecution Insights
Last updated: August 15, 2026
Application No. 18/307,802

BIODEGRADABLE AND POLYMERIZABLE POLYESTER COMPOSITION, BIODEGRADABLE POLYESTER RESIN OBTAINED THEREFROM, AND PREPARATION METHOD THEREOF

Final Rejection §103
Filed
Apr 27, 2023
Priority
May 23, 2022 — RE 10-2022-0063075
Examiner
KOLB, KATARZYNA I
Art Unit
1767
Tech Center
1700 — Chemical & Materials Engineering
Assignee
SK Leaveo Co. Ltd.
OA Round
2 (Final)
45%
Grant Probability
Moderate
3-4
OA Rounds
5m
Est. Remaining
61%
With Interview

Examiner Intelligence

Grants 45% of resolved cases
45%
Career Allowance Rate
97 granted / 217 resolved
-20.3% vs TC avg
Strong +16% interview lift
Without
With
+16.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
53 currently pending
Career history
270
Total Applications
across all art units

Statute-Specific Performance

§101
1.3%
-38.7% vs TC avg
§103
50.5%
+10.5% vs TC avg
§102
21.4%
-18.6% vs TC avg
§112
15.0%
-25.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 217 resolved cases

Office Action

§103
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 . Response to Arguments In their response dated 5/1/2026 the applicants argued following: 1). With respect to the content of the inorganic filler, the applicants limited to content of the filler to 3-10% by weight and argued that examples 2-5 of the instant invention show that 3% of the filler shows better barrier properties with respect to 1% of the filler in example 1. Applicant concluded that the Coszach fails to teach the amount of the inorganic filler. Response: Applicants are correct. The teachings of Nyun were utilized to meet the content of filler. 2). Nyun discloses that the additive silica is preferably utilized in amount of 2% by weight or less and indicates that transparency deteriorates if amount is higher than 3% by weight. Response: While Nyun may recite the preferred range to be 2% by weight or less, the preferred embodiment does not teach away from overall teachings. Nyun does enable one of ordinary skill in the art to utilize the amount of up to 3% by weight (3% inclusive) wherein the amount overlaps with claimed range. Having said that another reference will be provided to show narrower content of silica which still affords transparent article. 3). Teachings of Gui do not remedy the deficiencies of Coszach and Nyun. Nelson was utilized in a separate rejection for its addition of nanocellulose as a dispersant. The applicants further disagree with characterization of Gui without indicating any errors in the characterization of the reference. Response: Gui was utilized to reject dependent claims 5-8 and 10-13. Nelson was utilized to reject claim 9. The applicants have not argued grounds of rejection. In his arguments the applicants relied upon instant examples, which were reviewed by the applicants. While reviewing the examples the examiner noted that the metal of claim 5 was not disclosed in any examples. Instant specification discloses that metals contained in the biodegradable polyester are selected from group consisting of Si, Ca, Ti, Ba and Al. Preferred are Si, Ca and Ti. First Si is not a metal as it is in the same group on the periodic table as C and therefore it is a metalloid at best. The specification clearly states metals not metal compounds which includes elemental metals. The applicants are therefore put on notice to provide explanation as to when metals are utilized exactly and how they are utilized. Since instant specification discloses only inorganic fillers which accidentally are titania, calcium carbonate and silica which contain Ca, Si and Ti, it is not clear if the Ca, Si and Ti referred to as metals are the same as the inorganic filler or if the metals of claim 5 are something entirely different. If the metal of claim 5 are different in nature than inorganic fillers, the use of these metals especially when amounts can be as high as 7% lack written description. Clarification is required. Specification The disclosure is objected to because of the following informalities: Similarly to the claims, instant specification also contains error with respect to characterization of the viscosity were intrinsic viscosity is reported in poise. During the short discussion with applicant’s representative Minh-Quan K. Pham suggested removing term intrinsic and just leave the viscosity as being reported in poise. However, the examiner indicated that such amendment would not be proper because in addition to dynamic viscosity because instant specification also discloses melt viscosity of the PLA resin which can also be measured using poise or pascal-seconds. Consequently, not all viscosities in applicants’ invention measured in poise are dynamic viscosity and that distinction has to be maintained. Appropriate correction is required. Claim Interpretation With respect to ASTM standards utilized in the claims following are ISO and JIS equivalents: ASTM D638 V has equivalent in ISO 527-2 Type 5B and JIS K7161 ASTM D3985 has equivalent in ISO 15105-2 and JIS K7126-2-B ASTM D1003 has equivalent in ISO 14782 and JIS K7136 JIS B0601 has equivalent in ISO 4287:1997 and ASTM : ASME B46.1 With respect to the Equation 1: PNG media_image1.png 78 314 media_image1.png Greyscale While applicants can be their own lexicographers, the extent of which should not contradict the definitions already established in the art. Dispersion Index of a filler is measured by quantifying the spatial distribution, size and uniformity of a filler particles within matrix is accomplished using microscopic imaging, light scattering or spectroscopic techniques. Dispersity of the filler cannot be directly measured from the equation 1, because tensile strength and oxygen permeability are composite performance indicator influenced by many factors such as particle shape, interfacial adhesion, loading dispersion as such they do not represent a direct physical measurement of the particle size distribution. Consequently, the prior art of record will encompass claimed dispersion index as long as the properties of tensile strength and oxygen permeability are within the same range. With respect to equation 2: PNG media_image2.png 76 408 media_image2.png Greyscale Similarly with the discussion of Formula 1, by definition the measuring the processability reduction index in polymers index involves assessing changes in viscosity, glow behavior, and thermal stability, often quantified by the melt flow index of capillary rheometry. A decrease in processability indicates higher viscosity or degradation is reflected by reduction in MFI at a specific temperature and load. It should be noted that this type of measurement has its own ASTM D1238 standard that is not utilized in the instant invention. While surface roughness is major contributor to total haze, it is not the only contributor. Surface roughness is further influenced by include high melt elasticity or crystallization. It is important to note that total haze includes both surface haze (due to roughness) and internal bulk has (due to crystallization /density changed. Consequently, surface roughness is not reflective of the entirety of the haze. Consequently, if the prior art of record meets the limitation of surface roughness and haze, the prior art will meet the limitation of processability reduction index. With respect to of recitation of ring opening process in the composition claims, the limitation is viewed as product by process. Consequently, the patentable weight is given to the product and not to the process by which it was made. With respect to the limitation of monomers and/or prepolymers utilized in making polymerizable composition, the aliphatic-aromatic component is selected from a monomer composition comprising diol component and dicarboxylic acid component and a prepolymer of part or all of the monomer composition. As such, under broadest reasonable interpretation, the prepolymer comprising all of the monomers reads on fully polymerized polymer. 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. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Coszach (US 2006/0014975) in view of Nyun (KR 2005-0056020 translation attached). With respect to claim 1, Coszach discloses a method of polymerizing polylactic acid in situ with fillers and additives in order to make a biodegradable composition [0072] and with optical quality [0022, 0153]. The composition is utilized to make packaging [0109]The composition Specifically [0144] of Coszach discloses following composition: Purified lactide as monomer in presence, Catalyst (tin octanoate, triphenylphosphine) A prepolymer having molecular weight in a range of 10,000-50,000, Additives which includes fillers, stabilizers and if required catalytic deactivators are added with lactide monomer. Consistent with broadest reasonable interpretation above, a prepolymer having molecular weight in a range of 10,000-50,000, the molecular weight of the prepolymer produced is encompassed by a range of disclosed in the specification. Once polymerized the molecular weight of the polymer of Coszach is 40,000 up to 350,000 which also encompasses the molecular weight of the instant invention. While Coszach discloses use of fillers, the jest of his invention lies in the polymerization process and when the additives can be incorporated into polymeric composition in order to form a product having good optical quality. As it is well understood in the art the type of the filler and the content in which such filler can be utilized depends on the intended use of the polymeric composition [0106]. Nyun discloses a composition which also requires optical transparency and is also utilized in the making of packaging materials just like the composition of Coszach. The majority of the composition of Nyun is also polylactic acid (PLA) in order to maintain transparency (p. 3 of the translation, last sentence. Nyun also discloses use of aliphatic-aromatic polyester that is blended with the PLA to further improve not only transparency but also elongation, tensile strength and release property. Nyun discloses use of fillers such as silica, in amount of 0.05-3 % by weight (claim 3). The content of silica as disclosed by Nyun is utilized in order to aid in release properties of the film (page 4 of the translation). Consequently, it would have been obvious to one having ordinary skill in the art at the time instant invention is filed to utilize the silica of Nyun in the composition of Coszach and thereby obtain the claimed invention. Use of silica of Nyun in the claimed amount will not adversely affect transparency of the composition and such composition can still be utilized to make packaging in food industry. Consequently, using silica in such amounts would therefore also result in the composition having claimed viscosity, because not only PLA is the same but also type and content of the filler, including particle size and BET. With respect to claims 2 and 3, as it was disclosed above the Nyun discloses use of no more than 3%,wherein silica is defined particle size in a range of 2-20 microns and surface area of 100-600 m2/g (page 4 of translation). The specific tradename of the silica utilized by Nyun is FPS-11 by Shionogi Co, which has BET of 175-225 m2/g (page 5 of translation, experimental section). With respect to claim 4, the silica of Nyun is wet processed by extruder, which encompasses the definition of homogenizer as it acts as high shear mixer. Wet processed silica is then added to the composition. It should also be noted that the composition of Nyun is subject to ASTM D1003 and results in haze value of less than 10% (page 4). Claims 5-8 and 10-13 are rejected under 35 U.S.C. 103 as being unpatentable over Coszach (US 2006/0014975) in view of Nyun (KR 2005-0056020 translation attached) as applied to claims 1-4 above, and further in view of Gui (WO 2021/185339) US 2023/0193021 is used as translation. Discussion of Coszach and Nyun from paragraph 1 of this office action is incorporated here by reference. In summary, Coszach discloses process of making biodegradable polymer composition having optical properties and transparency. The composition of Coszach discloses use additives utilized in the second condensation reaction added with lactide stream to the prepolymer, wherein additives include fillers. Nyun is utilized to supplement the type and amount of filler that can be utilized in the composition of Coszach without negatively affecting the transparency and processability of the composition. The composition of Coszach is utilized as packaging material in food industry. While Coszach discloses composition his invention is directed mainly to the process in which the lactide is polymerized. Gui who also teaches composition that includes PLA biodegradable polymer in the same packaging industry and what properties are required for the composition to make good product and at the same time be compostable at the end of service life (Abstract). Gui discloses composition comprising at least 70%, most preferably at least 85% of polylactic acid [0013] because its use helps to improve the processing properties and the usability such as mechanical properties and thermal properties [0014]. The polylactic acid of Gui has number average molecular weight of 50,000 or more [0015] which is within the range of the molecular weight of the Coszach, Nyun and instant invention. The optical purity of PLA is at least 97%, which is also the purity required by Coszach [0016]. In order to speed up the biodegradation process and improve the properties such as flexibility, elongation, thickness deviation of film products the composition may comprise aliphatic-aromatic copolyester in amount of 10-30 wt.% [0027]. The fillers of Gui also include silica as well as calcium carbonate, titania, alumina. Organic fillers include cellulose [0033]. The silica is the filler disclosed in the Coszach and Nyun, wherein physical properties are already met by Nyun. Gui discloses that the content of metallic element is 50-500 ppm [0030, 0055-0056] which is equivalent to 0.005-0.05% which range encompasses claimed range. Addition of such metal is also utilize to increase biodegradation and improve mechanical properties, because metallic element facilitated reactions such as ester exchange and chain expansion between PLA and other resins of additives. The properties of the composition of Gui are as follows: Intrinsic viscosity of 1.0 dL/g or more [0007], and since the PLA has the same number average molecular weight as consulted with instant specification, as well as exactly the same monomer make up as both instant invention and Coszach, the PLA of Gui will also meet the viscosity. Oxygen Permeability according to a standard ASTM D3952 [0125] is less than 500 cc/m2 [0129]. Tensile strength of 60 MPa or more (claim 34) while the ASTM methos was not disclosed the sample was subject to tensile speed of 100 mm/min which is the same tensile speed as ASTM D638 V [0122]. Haze and transparency, the article of Gui has transparency of at least 90%, haze of 40% or less and internal haze of 8%. While claims do not distinguish which haze measurement is claimed, both values of Gui meet the claimed range [0064]. While Gui does not disclose the ASTM method, such method is disclosed in Nyun and results in the same overlapping ranges as that of instant invention and Gui. Roughness of 0.05-0.5 microns [0066], wherein 0.05 microns meets the claimed amount. While the roughness method is not defined, and Gui does not specify if the roughness measurement is a centerline measurements, the following is well established in the art: Centerline roughness is commonly known as average roughness or arithmetic average. It measures the arithmetic average of the absolute values of surface height and deviation (peaks and valleys) within specified sampling length. Gui discloses that the film produced therein is uniform and the variation of the film thickness is 10% or less [0068]. In fact, the examples disclosed in Table 3 have variation in thickness of less than that. Consequently, for the film that is uniform is viewed as an average measurement with the +/- 10% or less variation. While coefficient of friction is not disclosed, this property depends on material composition, surface roughness and surface contaminants, which for purpose of this rejection will be viewed as negligible or none. Since all disclosures of record disclose PLA composition comprising filler such as silica, and the content of silica is what influences surface roughness and since roughness influences coefficient of friction, the composition as disclosed in Gui will meet the instantly claimed coefficient of friction. With respect to claim 5, based on the summary of the properties in Gui above, the dispersion index as claimed by the applicants has tensile strength is 60 MPa or more oxygen permeability of 500 or less and metal content of 0.005-0.05%. The dispersion index value is 12. With respect to claim 6, Ra is 50 nm and haze is 48% or less (including both surface haze and internal haze) the processability index will be less than 100. With respect to claim 7, please refer to all the properties disclosed in Gui as discussed above. With respect to claim 8, the biodegradable polymer of references utilized in the rejection is PLA, aliphatic-aromatic polyesters when blended with PLA include PBAT (See discussions above). With respect to claim 10, the limitation is not viewed as limitation that would narrow down the scope of the polymer composition, but operational condition of the filter within the extruder. Having said that, the applicants defined the claims filter pressure difference in instant specification as dependent on inorganic filler dispersion. Specifically, instant specification stated that if filler is well dispersed during the condensation of the polyester, the filter pressure difference is small. If the inorganic filler particles are not well dispersed, aggregation may take place and cause filter clogging. In all references applied in this rejection uniform distribution of the filler is a must. Coszach as disclosed in paragraph 1 of this rejection adds filler during the polymerization of the lactic acid, in order to obtain product having good optical properties. It is well established fact in the art that aggregated particles will affect transparency of the film and increase opacity. Nyun pretreats silica to homogenize it, wherein it is another well-established knowledge that homogenizing filler is done to break up aggregates and allow uniform dispersion of the filler. Resulting sheet of Nyun as disclosed in paragraph 1 of this rejection has the same haze and transparency as instant invention. Gui discloses importance of uniformly dispersed filler so that uniform surface roughness can be obtain which in turn will directly affect the permeability of the film or a sheet. Since all these properties as disclosed by the prior art of record meet the claimed properties the change in pressure applied to the filter will also be within the same range. With respect to claims 11-13, primary reference of Coszach disclosed multi-step condensation of polylactic acid first by ring opening and forming prepolymer and the adding monomers and additives to complete condensation of monomers and provide composition for making packaging material for food industry. This topic is presented in detail in paragraph 1 of this rejection. Gui was utilized to supplement the properties of the same type of polylactic polymer (molecular weight and viscosity) necessary for the composition to be suitable as food packaging product. These properties are defined in rejection of instant claim 5 and claim 7 respectively. Polymerization of the PLA is disclosed in rejection of claim 1. In the light of the above disclosure, at the time instant invention was filed, it would have been obvious to one having ordinary skill in the art to utilize known process of Coszach to polymerize polylactic acid for the production of the transparent food packaging articles. It would have been obvious to one having ordinary skill in the art at the time instant invention was filed, to adjust the properties of the polymer composition of Coszach as it is shown in Gui, since the properties of Gui are necessary to form efficient packaging material that is also compostable thereby minimizing impact on the environment. Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Coszach (US 2006/0014975) in view of Nyun (KR 2005-0056020 translation attached) and Gui [(WO 2021/185339) US 2023/0193021 is used as translation] as applied to claims 1-8 and 10-13 above, and further in view of Nelson (US 2018/0118936. Discussion of Coszach and Nyun from paragraph 1 of this rejection is incorporated here by reference. The discussion of Gui from paragraph 2 of this rejection is also incorporated here by reference. Coszach in his polymerization process discloses purification and melt processing which are require crystallization and utilize various ways to promote nucleation and the grown of crystals by seeding pure lactide crystals [0166]. The additives include dispersants. Gui further teaches use of nucleating agents and dispersants (WO document). While Gui discloses cellulose, reference lacks the description of the cellulose. Nelson discloses composition comprising transparent polylactic acid, which is also utilized to make food packaging, wherein nucleating agents are specifically preferred for biodegradable polymer such as polylactic acid (Abstract). Nelson teaches that in order to improve heat resistance of PLA one of ordinary skill in the art can partially crystalize it [0005] and there are two ways to do it. First by annealing which can negatively impact the final product (for example, by shrinking), and second process is by slow crystallization which takes a long time [0006] not very economical on industrial scale). Nelson therefore provides solution where polylactic acid polymer can have improved crystallization much faster than slow crystallization and one that does not deteriorate the physical properties of the composition. Nelson achieves this by adding nucleating agent which is based on nanocellulose. Nanocellulose is added to the polylactic acid along with an additive such as silica [0023, 0072], wherein content of the nanocellulose is 0.1-10 % by weight which functions as a dispersant nucleating agent [0017] or a dispersant [0051]. The length-to-width aspect ratio of nanocellulose particles is from 10-1000, wherein the length is 10-500 nm [0161]. It would have been obvious to one having ordinary skill in the art at the time instant invention was filed to utilize nanocellulose of Nelson in the composition of Coszach and thereby obtain the claimed invention. Use of nanocellulose will also result in a composition having improved thermal stability for processing the composition into an article, wherein the resulting article is also a food packaging [0134] while maintaining transparency [0195], oxygen permeability [0104], tensile strength [0103]. Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Coszach (US 2006/0014975) in view of Koyama (US 2020/0181394). Evidentiary references Aerosil R972 data sheet and US 2012/0277362 used to support examiner’s position regarding the BET limitation for two tradenames of silica used in examples of Koyama only. They are not used as prior art. With respect to claim 1, Coszach discloses a method of polymerizing polylactic acid in situ with fillers and additives in order to make a biodegradable composition [0072] and with optical quality [0022, 0153]. The composition is utilized to make packaging [0109]The composition Specifically [0144] of Coszach discloses following composition: Purified lactide as monomer in presence, Catalyst (tin octanoate, triphenylphosphine) A prepolymer having molecular weight in a range of 10,000-50,000, Additives which includes fillers, stabilizers and if required catalytic deactivators are added with lactide monomer. Consistent with broadest reasonable interpretation above, a prepolymer having molecular weight in a range of 10,000-50,000, the molecular weight of the prepolymer produced is encompassed by a range of disclosed in the specification. Once polymerized the molecular weight of the polymer of Coszach is 40,000 up to 350,000 which also encompasses the molecular weight of the instant invention. While Coszach discloses use of fillers, the jest of his invention lies in the polymerization process and when the additives can be incorporated into polymeric composition in order to form a product having good optical quality. As it is well understood in the art the type of the filler and the content in which such filler can be utilized depends on the intended use of the polymeric composition [0106]. Koyama discloses a composition comprising aliphatic and aliphatic-aromatic biodegradable polymers. The composition requires good transparency [0057], moldability and mechanical properties [0010, 0027]. The composition of Koyama is also comprises silica in an amount of 8-23 parts [0021]. Examples utilize silica usually in amount of 10 parts (examples 1-7), 5 parts (example 8). The content of the silica is utilized to the extent where the transparency of the composition is not impaired [0057]. Silica of Koyama is pretreated to adjust the moisture adsorbed onto its surface to be in a range of 0.5-7% because moisture content of above 7% the dispersion of the silica will be negatively impacted. If the moisture content is less than 0.5% then the small amount of moisture will form crosslinked liquid film resulting in large bonding surface which is also difficult to disperse. The pretreatment meets the limitation of claim 4, wherein the equipment utilized to pretreat the silica is process steps (product by process) wherein patentable weight is given to the composition and not process by which is weas made or obtained. The treatments includes rendering silica hydrophobic [0054]. With respect to the dynamic viscosity the PLA of Coszach has molecular weight within range overlapping the molecular weight of the PLA of the instant invention. Since filler utilized is silica with the amount, particle size and BET within claimed ranges, its effect on the viscosity will be the same as in the instant application. This is because viscosity not only is dependent on the filler type, particles size and amount but also on the specific polymer and its molecular weight. Consequently, if the composition of claim 1 only requires one pre-polymer with the same amount and type of the filler then the dynamic viscosity will overlap as well. Specifically, the attention is drawn to filler being used in amount of 5 and 10 parts as amounts that do not adversely affect the transparency of the biodegradable film. With respect to claims 2 and 3, the silica of Koyama has to have particle size in a range of 0.001-0.1 microns, preferably 0.005-0.05 microns which is less than claimed 15 microns or less. While Koyama does not explicitly disclose the BET of the silica, he discloses the tradenames. The silicas disclosed are Nipsil LP a wet silica, manufactured by Tosoh Silica Corporation and R972 dry silica manufactured by Nippon Aerosil CO LTD. Datasheet for Aerosil’s R 972 reports BET of 30-130 m2/g, US 2012/0277362 for Nipsil LP reports BET 200 m2/g. Examples further disclose use of calcium carbonate, magnesium hydroxide, magnesium oxide and the like. In the light of the above disclosure, it would have been obvious to one having ordinary skill in the art at the time instant invention was filed to utilize silica of Koyama in the composition of Coszach and thereby obtain the claimed invention. Specifically, Coszach allows use of fillers to obtain transparent article, while Koyama discloses fillers in amounts such that transparency of the composition is not adversely affected. Claims 5-8 and 10-13 are rejected under 35 U.S.C. 103 as being unpatentable over Coszach (US 2006/0014975) in view of Koyama (US 2020/0181394) as applied to claims 1-4 above, and further in view of Gui (WO 2021/185339) US 2023/0193021 is used as translation. Discussion of the teachings of Coszach and Koyama from paragraph 4 of this office action is incorporated here by reference. In summary, Coszach and Koyama disclose composition comprising silica as a filler which is utilized to produce transparent articles. The composition comprises mixture of aliphatic and aliphatic-aromatic biodegradable polymers. Composition is utilized to mold transparent food containers. However, Coszach is silent with respect to the properties of transparent film and its barrier properties. Gui discloses composition comprising at least 70%, most preferably at least 85% of polylactic acid [0013] because its use helps to improve the processing properties and the usability such as mechanical properties and thermal properties [0014]. The polylactic acid of Gui has number average molecular weight of 50,000 or more [0015] which is within the range of the molecular weight of the Coszach, Koyama and instant invention. The optical purity of PLA is at least 97%, which is also the purity required by Coszach [0016]. In order to speed up the biodegradation process and improve the properties such as flexibility, elongation, thickness deviation of film products the composition may comprise aliphatic-aromatic copolyester in amount of 10-30 wt.% [0027]. The fillers of Gui also include silica as well as calcium carbonate, titania, alumina. Organic fillers include cellulose [0033]. The silica is the filler disclosed in the Coszach and Koyama, wherein physical properties are already met by Koyama. Gui discloses that the content of metallic element is 50-500 ppm [0030, 0055-0056] which is equivalent to 0.005-0.05% which range encompasses claimed range. Addition of such metal increases biodegradation and improve mechanical properties, because metallic element facilitated reactions such as ester exchange and chain expansion between PLA and other resins of additives. The properties of the composition of Gui are as follows: Intrinsic viscosity of 1.0 dL/g or more [0007], and since the PLA has the same number average molecular weight as consulted with instant specification, as well as exactly the same monomer make up as both instant invention and Coszach, the PLA of Gui will also meet the required dynamic viscosity. Oxygen Permeability according to a standard ASTM D3952 [0125] is less than 500 cc/m2 [0129]. Tensile strength of 60 MPa or more (claim 34) while the ASTM methos was not disclosed the sample was subject to tensile speed of 100 mm/min which is the same tensile speed as ASTM D638 V [0122]. Haze and transparency, the article of Gui has transparency of at least 90%, haze of 40% or less and internal haze of 8%. While claims do not distinguish which haze measurement is claimed, both values of Gui meet the claimed range [0064]. While Gui does not disclose the ASTM method, the amounts and results are in the same overlapping ranges as that of instant invention and Gui. Roughness of 0.05-0.5 microns [0066], wherein 0.05 microns meets the claimed amount. While the roughness method is not defined, and Gui does not specify if the roughness measurement is a centerline measurements, the following is well established in the art: Centerline roughness is commonly known as average roughness or arithmetic average. It measures the arithmetic average of the absolute values of surface height and deviation (peaks and valleys) within specified sampling length. Gui discloses that the film produced therein is uniform and the variation of the film thickness is 10% or less [0068]. In fact, the examples disclosed in Table 3 have variation in thickness of less than that. Consequently, for the film that is uniform is viewed as an average measurement with the +/- 10% or less variation. While coefficient of friction is not disclosed, this property depends on material composition, surface roughness and surface contaminants, which for purpose of this rejection will be viewed as negligible or none. Since all disclosures of record disclose PLA composition comprising filler such as silica, and the content of silica is what influences surface roughness and since roughness influences coefficient of friction, the composition as disclosed in Gui will meet the instantly claimed coefficient of friction. With respect to claim 5, based on the summary of the properties in Gui above, the dispersion index as claimed by the applicants has tensile strength is 60 MPa or more oxygen permeability of 500 or less and metal content of 0.005-0.05%. The dispersion index value is 12. With respect to claim 6, Ra is 50 nm and haze is 48% or less (including both surface haze and internal haze) the processability index will be less than 100. With respect to claim 7, please refer to all the properties disclosed in Gui as discussed above. With respect to claim 8, the biodegradable polymer of references utilized in the rejection is PLA, aliphatic-aromatic polyesters when blended with PLA include PBAT (See discussions above). With respect to claim 10, the limitation is not viewed as limitation that would narrow down the scope of the polymer composition, but operational condition of the filter within the extruder. Having said that, the applicants defined the claims filter pressure difference in instant specification as dependent on inorganic filler dispersion. Specifically, instant specification stated that if filler is well dispersed during the condensation of the polyester, the filter pressure difference is small. If the inorganic filler particles are not well dispersed, aggregation may take place and cause filter clogging. In all references applied in this rejection uniform distribution of the filler is a must. Coszach as disclosed in paragraph 1 of this rejection adds filler during the polymerization of the lactic acid, in order to obtain product having good optical properties. It is well established fact in the art that aggregated particles will affect transparency of the film and increase opacity. Koyama pretreats silica to ensured uniform dispersion throughout the polymer matrix, wherein it is another well-established knowledge that pretreating filler is minimize formation of aggregates and allow uniform dispersion of the filler. Resulting film of Koyama as disclosed in paragraph 1 of this rejection has the same haze and transparency as instant invention and stresses the importance of proper dispersion. Gui also discloses importance of uniformly dispersed filler so that uniform surface roughness can be obtain which in turn will directly affect the permeability of the film or a sheet. Since all these properties as disclosed by the prior art of record meet the claimed properties the change in pressure applied to the filter will also be within the same range. With respect to claims 11-13, primary reference of Coszach disclosed multi-step condensation of polylactic acid first by ring opening and forming prepolymer and the adding monomers and additives to complete condensation of monomers and provide composition for making packaging material for food industry. This topic is presented in detail in paragraph 1 of this rejection. Gui was utilized to supplement the properties of the same type of polylactic polymer (molecular weight and viscosity) necessary for the composition to be suitable as food packaging product. These properties are defined in rejection of instant claim 5 and claim 7 respectively. Polymerization of the PLA is disclosed in rejection of claim 1. In the light of the above disclosure, at the time instant invention was filed, it would have been obvious to one having ordinary skill in the art to utilize known process of Coszach to polymerize polylactic acid for the production of the transparent food packaging articles. It would have been obvious to one having ordinary skill in the art at the time instant invention was filed, to adjust the properties of the polymer composition of Coszach as it is shown in Gui, since the properties of Gui are necessary to form efficient packaging material that is also compostable thereby minimizing impact on the environment. Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Coszach (US 2006/0014975) in view of Koyama (US 2020/0181394) and Gui [(WO 2021/185339) US 2023/0193021 is used as translation] as applied to claims 1-8 and 10-13 above, and further in view of Nelson (US 2018/0118936. Discussion of Coszach and Koyama from paragraph 4 of this rejection is incorporated here by reference. The discussion of Gui from paragraph 5 of this rejection is also incorporated here by reference. Coszach in his polymerization process discloses purification and melt processing which are require crystallization and utilize various ways to promote nucleation and the grown of crystals by seeding pure lactide crystals [0166]. The additives include dispersants. Gui further teaches use of nucleating agents and dispersants (WO document). While Gui discloses cellulose, reference lacks the description of the cellulose. Nelson discloses composition comprising transparent polylactic acid, which is also utilized to make food packaging, wherein nucleating agents are specifically preferred for biodegradable polymer such as polylactic acid (Abstract). Nelson teaches that in order to improve heat resistance of PLA one of ordinary skill in the art can partially crystalize it [0005] and there are two ways to do it. First by annealing which can negatively impact the final product (for example, by shrinking), and second process is by slow crystallization which takes a long time [0006] not very economical on industrial scale). Nelson therefore provides solution where polylactic acid polymer can have improved crystallization much faster than slow crystallization and one that does not deteriorate the physical properties of the composition. Nelson achieves this by adding nucleating agent which is based on nanocellulose. Nanocellulose is added to the polylactic acid along with an additive such as silica [0023, 0072], wherein content of the nanocellulose is 0.1-10 % by weight which functions as a dispersant nucleating agent [0017] or a dispersant [0051]. The length-to-width aspect ratio of nanocellulose particles is from 10-1000, wherein the length is 10-500 nm [0161]. It would have been obvious to one having ordinary skill in the art at the time instant invention was filed to utilize nanocellulose of Nelson in the composition of Coszach and thereby obtain the claimed invention. Use of nanocellulose will also result in a composition having improved thermal stability for processing the composition into an article, wherein the resulting article is also a food packaging [0134] while maintaining transparency [0195], oxygen permeability [0104], tensile strength [0103]. 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. Correspondence Any inquiry concerning this communication or earlier communications from the examiner should be directed to KATARZYNA I KOLB whose telephone number is (571)272-1127. The examiner can normally be reached M-F. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Mark Eashoo can be reached at 5712701046. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /KATARZYNA I KOLB/Primary Examiner, Art Unit 1767 May 21, 2026
Read full office action

Prosecution Timeline

Apr 27, 2023
Application Filed
Feb 03, 2026
Non-Final Rejection mailed — §103
May 01, 2026
Response Filed
May 27, 2026
Final Rejection mailed — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
45%
Grant Probability
61%
With Interview (+16.3%)
3y 9m (~5m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 217 resolved cases by this examiner. Grant probability derived from career allowance rate.

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