DETAILED ACTION
This office action follows a response filed on December 8, 2025. Claims 1, 7, 12, 14, 23, 46, and 48 were amended. Claim 2 was canceled, and new claim 53 was added. Claims 1, 3-12, 14, 18, 21-23, 25, 28-30, and 44-53 are pending.
Claim Objections
Claims 3, 28, and 30 are objected to because of the following informalities: Claims depend from canceled claim 2.
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, 3-6, 12, 18, 21-23, 25, 44-47, and 50-52 are rejected under 35 U.S.C. 103 as being unpatentable over Tomka (US 5,415,827).
Tomka teaches preparation of a polymer blend comprising 75 kg of natural starch with a moisture content of less than 0.3 wt %, 25 kg of glycerine, 50 kg of high density polyethylene, and 50 kg of ethylene-acrylic acid ethyl ester-maleic acid copolymer as phasing agent. The phasing agent, together with use of susbstantially moisture free starch, prevents phase separation between the starch and polymer phase (col. 2, line 65 – col. 3, line 5; col. 4, lines 45-48). Additionally, the phasing agent lowers the melting point of the starch so that the melting point of the starch-phasing agent mixture lies below the decomposition temperature of the starch (claim 1). The components are melt-mixed and granulated. The granulated polymer blend is dried to reduce the moisture content to less than 1 % and then used to prepare blown film which is subsequently stretched at 130 ºC with a stretch ratio of 1:6 to 1:7.5 in one direction.
Reference does not quantify shear stress of the composition as it passes through a die. In light of the fact that inventors teach a critical shear stress of a starch-polymer blend is greater than a critical shear stress of the polymer alone, thereby extending onset of melt flow instability, and in view of the fact that prior art process results in successful formation of stretched film, one of ordinary skill in the art would reasonably conclude that the composition of prior art process exhibits claimed shear stress being below an onset of melt flow instability of the composition. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02. Tomka is also silent with regard to the morphology of the polymer blend, however, one of ordinary skill in the art would expect at least some of the starch and high density polyethylene will be blended together intimately as described in instant claims. Again, the burden is shifted to the Applicants to establish an unobviousness differences between claimed material and that of the prior art.
While working examples show preparation of monoaxially stretched film, one of ordinary skill in the art would have found it obvious to prepare biaxially stretched film (col. 2, line 59; col. 7, line 33; claim 1). In addition to polyethylene, one of ordinary skill in the art would have found it obvious to carry out invention of prior art using polypropylene (col. 7, line 24). In the cited example, the starch constitutes 43 wt % of the total composition, but the skilled artisan would have found it obvious to use an amount from 30 wt % to 70 wt % (claim 13).
Claims 7, 48, and 49 are rejected under 35 U.S.C. 103 as being unpatentable over Shi et al. (US 8,329,601).
Shi et al. discloses preparation of a biodegradable film comprising a mixture of 57 wt % of Ecoflex F BX 7011 (polybutylene adipate terephthalate; PBAT) resin, 28 wt % of thermoplastic starch/gluten (70/30 ratio), and 15 wt % filler. The thermoplastic starch is commercially available as Glucosol 800 and has a weight average molecular weight of 2,900,000 (col. 19, line 11).
Reference does not quantify shear stress of the mixture as it passes through a die. In light of the fact that inventors teach a critical shear stress of a starch-polymer blend is greater than a critical shear stress of the polymer alone, thereby extending onset of melt flow instability, and in view of the fact that prior art process results in successful formation of stretched film, one of ordinary skill in the art would reasonably conclude that the composition of prior art process exhibits claimed shear stress being below an onset of melt flow instability of the composition. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02. Shi et al. is also silent with regard to the morphology of the polymer blend, however, one of ordinary skill in the art would expect at least some of the thermoplastic starch and polybutylene adipate terephthalate will be blended together intimately as described in instant claims. Again, the burden is shifted to the Applicants to establish an unobviousness differences between claimed material and that of the prior art.
Claims 1, 12, 14, 18, 22, 23, 25, 28-30, 44, 45, and 50-52 are rejected under 35 U.S.C. 103 as being unpatentable over Shi et al. (US 8,329,601) in view of Tomka (US 5,415,827).
Shi et al. discloses preparation of a biodegradable film comprising a mixture of 57 wt % of Ecoflex F BX 7011 (polybutylene adipate terephthalate; PBAT) resin, 28 wt % of thermoplastic starch/gluten (70/30 ratio), and 15 wt % filler. The thermoplastic starch is commercially available as Glucosol 800 and has a weight average molecular weight of 2,900,000 (col. 19, line 11), and it constitutes 19.6 wt % of the mixture. A film is made by melt extruding the mixture through a die and stretching the film at 100 % (2X) and 150 % (2.5X) in a machine direction. While working examples show preparation of biodegradable film stretched in a single (machine) direction, one of ordinary skill in the art would have found it obvious that preparation of biaxially stretched film is another embodiment of the invention (col. 16, line 45).
Reference does not quantify shear stress of the mixtures as they pass through a die. In light of the fact that inventors teach a critical shear stress of a starch-polymer blend is greater than a critical shear stress of the polymer alone, thereby extending onset of melt flow instability, and in view of the fact that prior art process results in successful formation of stretched film, one of ordinary skill in the art would reasonably conclude that the composition of prior art process exhibits claimed shear stress being below an onset of melt flow instability of the composition. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02. Shi et al. is also silent with regard to the morphology of the mixture, however, one of ordinary skill in the art would expect at least some of the thermoplastic starch and polybutylene adipate terephthalate will be blended together intimately as described in instant claims. Again, the burden is shifted to the Applicants to establish an unobviousness differences between claimed material and that of the prior art.
Shi et al. is silent regarding the water content of the starch. However, one of ordinary skill in the art would have found it obvious from Tomaka to reduce the moisture content of starch to less than 1 % to prevent phase separation between the starch and polymer phase.
Claims 7-11, 46, 48, and 49 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 8,466,337).
Wang et al. discloses preparation of a biodegradable film comprising a mixture of 57 wt % of Ecoflex F BX 7011 (polybutylene adipate terephthalate; PBAT) resin, 28 wt % of thermoplastic starch/gluten (70/30 ratio), and 15 wt % filler. The thermoplastic starch is commercially available as Glucosol 800 and has a weight average molecular weight of 2,900,000. A film is made by melt extruding the mixture through a die and stretching the film; biaxial stretching of the film produces even greater void formation and enhanced breathability of the film (col. 13, line 23).
Tables 6 and 7 reveals film properties of biodegradable film (Example 3) prepared from a composition comprising 52.5 wt % of Ecoflex F BX 7011 (polybutylene adipate terephthalate; PBAT) resin, 22.5 wt % of thermoplastic starch, and 25 wt % of filler. The starch is a native corn starch that has a weight average molecular weight of 6,380,000 (col. 5, line 25). Although the film is stretched in a machine direction, the breathability of the film is markedly enhanced when it is subjected to biaxial stretching (col. 16, line 2).
Reference does not quantify shear stress of the mixtures as they pass through a die. In light of the fact that inventors teach a critical shear stress of a starch-polymer blend is greater than a critical shear stress of the polymer alone, thereby extending onset of melt flow instability, and in view of the fact that prior art process results in successful formation of stretched film, one of ordinary skill in the art would reasonably conclude that the composition of prior art process exhibits claimed shear stress being below an onset of melt flow instability of the composition. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02. Wang et al. is also silent with regard to the morphology of the mixture, however, one of ordinary skill in the art would expect at least some of the thermoplastic starch and polybutylene adipate terephthalate will be blended together intimately as described in instant claims. Again, the burden is shifted to the Applicants to establish an unobviousness differences between claimed material and that of the prior art.
Claims 1, 2, 12, 14, 18, 22, 23, 25, 28-30, 44, 45, and 50-52 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 8,466,337) in view of Tomka (US 5,415,827).
Wang et al. discloses preparation of a biodegradable film comprising a mixture of 57 wt % of Ecoflex F BX 7011 (polybutylene adipate terephthalate; PBAT) resin, 28 wt % of thermoplastic starch/gluten (70/30 ratio), and 15 wt % filler. The thermoplastic starch is commercially available as Glucosol 800 and has a weight average molecular weight of 2,900,000, and it constitutes 19.6 wt % of the mixture. A film is made by melt extruding the mixture through a die and stretching the film; biaxial stretching of the film produces even greater void formation and enhanced breathability of the film (col. 13, line 23).
Tables 6 and 7 reveals film properties of biodegradable film (Example 3) prepared from a composition comprising 52.5 wt % of Ecoflex F BX 7011 (polybutylene adipate terephthalate; PBAT) resin, 22.5 wt % of thermoplastic starch, and 25 wt % of filler. The starch is a native corn starch that has a weight average molecular weight of 6,380,000 (col. 5, line 25). The film is stretched 300 % and 450 % in a machine direction. The breathability of the film is markedly enhanced when it is subjected to biaxial stretching (col. 16, line 2).
Reference does not quantify shear stress of the mixtures as they pass through a die. In light of the fact that inventors teach a critical shear stress of a starch-polymer blend is greater than a critical shear stress of the polymer alone, thereby extending onset of melt flow instability, and in view of the fact that prior art process results in successful formation of stretched film, one of ordinary skill in the art would reasonably conclude that the composition of prior art process exhibits claimed shear stress being below an onset of melt flow instability of the composition. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02. Wang et al. is also silent with regard to the morphology of the mixture, however, one of ordinary skill in the art would expect at least some of the thermoplastic starch and polybutylene adipate terephthalate will be blended together intimately as described in instant claims. Again, the burden is shifted to the Applicants to establish an unobviousness differences between claimed material and that of the prior art.
Wang et al. is silent regarding the water content of the starch. However, one of ordinary skill in the art would have found it obvious from Tomaka to reduce the moisture content of starch to less than 1 % to prevent phase separation between the starch and polymer phase.
Claims 1, 3, 4, 6, 12, 14, 23, 25, 30, 45, and 50-53 are rejected under 35 U.S.C. 103 as being unpatentable over Favis et al. (US 6,605,657).
Favis et al. teaches preparation of a polymer composition comprising a co-continuous blend of a thermoplastic starch and synthetic polymer wherein the co-continuous blend is constituted of a network of interconnected domains of thermoplastic starch and synthetic polymer. As explained by inventors, a co-continuous composition is one where both the thermoplastic starch and synthetic polymer are continuous such that the thermoplastic starch phase is dispersed in the polymer phase and the thermoplastic starch domains are nearly all interconnected (col. 6, lines 55-58). Tables 2 and 3 reveal exemplary polymer compositions containing thermoplastic starch and low density polyethylene, wherein the quantity of thermoplastic starch is in a range of 29.0 wt % to 53.3 wt %. The thermoplastic starch needs to be substantially water free (around 1 %) so that it can be blended with the low density polyethylene (col. 9, lines 22 and 36). The polymer composition is extruded through a rectangular die and quenched using calendar rolls which impose a machine direction deformation. SEM images show that blends show a fiber-like and nearly continuous morphology in the machine direction, confirming directional alignment of the polymer composition.
Favis et al. does not quantify shear stress of the mixtures as they pass through a die. In light of the fact that inventors teach a critical shear stress of a starch-polymer blend is greater than a critical shear stress of the polymer alone, thereby extending onset of melt flow instability, and in view of the fact that prior art process results in successful formation of stretched film, one of ordinary skill in the art would reasonably conclude that the composition of prior art process exhibits claimed shear stress being below an onset of melt flow instability of the composition. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02. Based on the description of morphology provide in prior art, one of ordinary skill in the art would expect at least some of the thermoplastic starch and low density polyethylene will be blended together intimately as described in instant claims. Again, the burden is shifted to the Applicants to establish an unobviousness differences between claimed material and that of the prior art.
Response to Arguments
Applicant traverses the rejection of claims in the response filed on December 8, 2025. Applicant submits that none of cited references teaches newly claimed feature wherein the starch-based polymeric material is intimately blended together with the at least one thermoplastic polymer such that at least some of the starch-based polymeric material is within the at least one thermoplastic polymer and wherein at least some of the thermoplastic polymer is within the starch-based polymeric material. Applicant points to SEM images of Shi et al., which show sea-island morphology that is representative of conventional thermoplastic starch-polymer blends.
Applicant’s arguments have been fully considered but they are not persuasive. The characterization of the blend of present invention is descriptive and qualitative but does not differentiate unambiguously from those of prior art. Moreover, claim states that “at least some” of the starch-based polymeric material is within the at least one thermoplastic and “at least some” of the thermoplastic polymer is within the starch-based polymeric material. The specification does not define quantitatively this amount, and one of ordinary skill in the art would not be apprised of what amount qualifies as “at least some”. One of ordinary skill in the art would expect at least some level of intimate blending to occur in the polymer blends of the prior art. It is noted that any attempt to differentiate inventions qualitatively by inspection of microscopy images depends on the level of resolution of these images. The SEM images in Shi et al. are not of the same level resolution as an image taken using photoinduced force microscopy (used by Applicant). Therefore, the SEM images do not appear to prove lack of intimate blending as recited in claims. That is, one cannot tell from images provided in Shi et al. that claimed characteristic of “at least some of the starch-based polymeric material is within the at least one thermoplastic and at least some of the thermoplastic polymer is within the starch-based polymeric material” does not exist. Applicant bears the burden of proof to establish any unobviousness differences between claimed invention and those of cited prior art. To date, Applicant has not furnished cogent evidence that would distinguish inventions.
Finally, Applicant contends that while compositions of Tomka require a phasing agent, blends of the present invention do not require a phasing agent. Claims as written, using the transitional phrase, comprising, do not exclude unrecited elements.
Based on these considerations, the rejections of record have been maintained.
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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/RIP A LEE/Primary Examiner, Art Unit 1762 March 5, 2026