DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12 May 2026 has been entered.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Rejections - 35 USC § 103
Claims 1-9 and 12-20 are rejected under 35 U.S.C. 103 as being unpatentable over Hiraki et al. (US 2020/0381679) in view of Nishida et al. (JP 2005-112994) as evidenced by Hu et al. (Polymer Composites, 37, pp 1049-1055) and Qualitest (Melt Flow Index vs Molecular Weight: A Technical Guide).
Hiraki is directed to a battery packaging material comprising a polybutylene terephthalate film (paragraph 0001). The battery packaging material is molded to form a concave portion into which battery elements, such as electrodes and electrolytic solutions, are disposed (paragraphs 0004-0005). The packaging comprising a polybutylene terephthalate base material layer, a barrier layer, a cured resin layer, and a heat-sealable layer (paragraph 0011). An adhesive is optionally present between the polybutylene terephthalate base material layer and the barrier layer (paragraph 0043).
Hiraki does not teach the presence of an acid-modified polymer and an amorphous thermoplastic resin in the polybutylene terephthalate base material layer.
Nishida is directed to a thermoplastic resin composition comprising a thermoplastic polyester, a rubber-modified polystyrene resin, a maleic anhydride-modified polystyrene resin, and a flame retardant (paragraph 0006). The composition may contain a reinforcing filler, such as glass fibers (paragraph 0025). The composition may be used for manufacturing electrical equipment parts (paragraph 0002) and exhibits excellent mechanical properties and dimensional accuracy as well as little warpage (paragraph 0036). In the embodiment of Example 4, the composition comprises 60 parts polybutylene terephthalate, 10 parts of high impact polystyrene, 30 parts maleic anhydride-modified polystyrene resin, 56 parts glass fiber, 20 parts pentabromobenzyl polyacrylate, and 8 parts antimony oxide (Table 1). The maleic anhydride-modified polystyrene resin has a maleic anhydride content of 8-10 wt% (paragraph 0037). The maleic anhydride-modified polystyrene resin represents 30/(60+10+30+56+20+8) ≈ 16 wt% of the composition. As such, the composition would contain about 1.2 wt% acid (for a maleic anhydride-modified polystyrene resin having 8 wt% maleic anhydride) to about 1.6 wt% acid (for a maleic anhydride-modified polystyrene resin having 10 wt% maleic anhydride).
It would have been obvious to one of ordinary skill in the art to use the composition of Nishida as the polybutylene terephthalate base material layer of Hiraki since Nishida teaches that the composition may be used for manufacturing electrical parts and the courts have held the selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination. See MPEP 2144.07. Moreover, the polybutylene terephthalate composition of Nishida is particularly suited for the molded packaging material of Hiraki since it exhibits little warpage and excellent dimensional stability.
Regarding the limitation in claim 1 directed to the weight average molecular weight of the acid-modified polymer, while Nishida teaches the use of a maleic anhydride-modified polystyrene resin having a weight average molecular weight of 240,000 and a melt flow rate of 2.0 g/10 min (paragraph 0037), this polymer is merely exemplary and there is no teaching that the maleic anhydride-modified polystyrene resin must have a weight average molecular weight of 240,000. However, Nishida does teach that the maleic anhydride-modified polystyrene resin preferably has a melt flow index of 0.5 to 15 g/10 min (paragraph 0018). Melt flow rate and molecular weight share an inverse relationship, which for many common plastics follows a power-law relationship where flow is related to the molecular weight raised to a power of about 3.4 (Qualitest, 6th and 7th paragraphs on page 2). As such, since a maleic anhydride-modified polystyrene resin exhibiting a melt flow rate of 2.0 g/10 min has a weight average molecular weight of 240,000, one of ordinary skill in the art would expect maleic anhydride-modified polystyrene resins having melt flow rates of 0.5 to 15 g/10 min to possess weight average molecular weights that overlap the ranges recited in claim 1 and claim 6. The courts have held that a prima facie case of obviousness exists for overlapping ranges. See MPEP 2144.05.
Regarding claims 1 and 12, the pentabromobenzyl polyacrylate (claim 1) and/or the high impact polystyrene (claims 1 and 12) correspond to the amorphous thermoplastic resin (C).
Regarding claim 13 and 14, the high impact polystyrene corresponds to the impact modifier comprising a core-shell elastomer (see the first paragraph of the Introduction of Hu describing high-impact polystyrene as having a core-shell structure.).
Regarding claim 19, Nishida teaches that the rubber-modified polystyrene resin may be a general-purpose polystyrene mixed with a copolymer formed by graft polymerizing styrene monomer in the presence of rubber (paragraph 0012). The general-purpose polystyrene reads on an amorphous thermoplastic resin comprising a styrenic resin while the copolymer formed by graft polymerizing styrene monomer in the presence of rubber (i.e., high impact polystyrene) reads on the core-shell elastomer.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Hiraki et al. (US 2020/0381679) in view of Nishida et al. (JP 2005-112994) as evidenced by Hu et al. (Polymer Composites, 37, pp 1049-1055) and Qualitest (Melt Flow Index vs Molecular Weight: A Technical Guide) as applied to claim 1 above, and further in view of Packham (Adhesion Science and Engineering, vol. 37, pp 1049-1055).
Hiraki taken in view of Nishida suggest all the limitations of claim 10, as outlined above, except for the arithmetic mean height of the polybutylene terephthalate film bonded to the barrier layer.
Packham discloses that the relevance of surface roughness to adhesion has long been recognized (page 317).
Since Packham shows that the relevance of surface roughness to adhesion has long been recognized, it would have been obvious to one of ordinary skill in the art to roughen the surface of the base material layer of Hiraki to improve the adhesion to the barrier layer or optional adhesive layer. Moreover, in the absence of any showing of criticality, it would have required no more than routine experimentation and ordinary skill to determine a suitable roughness and such experimentation would be expected to result in a surface having an arithmetic mean height satisfying the limitations of claim 10 since this arithmetic mean height is also chosen to improve adhesiveness (e.g., see paragraph 0018 on page 9 of the specification).
Response to Arguments
Applicant's arguments filed 12 May 2026 have been fully considered but they are not persuasive.
The applicant argues that Nishida does not teach or suggest the use of an acid-modified polymer having a weight average molecular weight of 200,000 or less. The applicant argues that setting the molecular weight to 200,000 or less results in an improved adhesiveness for the composition. The applicant notes that Nishida uses a maleic anhydride-modified polystyrene resin having a weight average molecular weight of 240,000 in the examples and provides no indication that reducing the molecular weight would be desirable or beneficial. The applicant alleges that the exclusive use by Nishida of a higher molecular weight maleic anhydride-modified polystyrene resin would discourage one of ordinary skill from lowering the molecular weight since it would be expected to adversely affect mechanical properties or heat resistance.
This is not persuasive for the following reasons. While the examples of Nishida employ a maleic anhydride-modified polystyrene resin having a melt flow rate of 2.0 g/10 min (and a weight average molecular weight of 240,000), the courts have held that disclosed examples do not constitute a teaching away from a broader disclosure (see MPEP 2123 II). In Nishida, the reference more broadly teaches that resin preferably has a melt flow rate of 0.5 to 15 g/10 min and Qualitest reveals that a known relationship would be expected to exist between the melt flow rate and molecular weight - specifically an inverse relationship wherein the flow rate is proportional to the molecular weight raised to a power of about 3.4. Based on the preferred range of melt flow rate explicitly recited by Nishida and the exemplified resin having a weight average molecular weight of 240,000 at a melt flow rate of 2.0 g/10 min, one of ordinary skill in the art would expect the maleic anhydride-modified polystyrene resin of Nishida (i.e., one having a melt flow rate of 0.5 to 15 g/10 min) to intrinsically possess a range of weight average molecular weights that overlap the ranges recited in the claims. Since the range of weight average molecular weight of the maleic anhydride-modified polystyrene resin would be expected to overlap range recited in the claims for the acid-modified polymer, a prima facie case of obviousness exists.
Regarding the applicant's contention that the use of an acid-modified polymer having a weight average molecular weight of 200,000 or less would result in an unexpected improvement in adhesion that would not have been predictable based on the disclosures of the prior art, while the examiner concedes that a showing of unexpected results may be used to show non-obviousness, the showing must be commensurate in scope with the claims. It is noted that, while claim 1 merely require a crystalline thermoplastic resin, an amorphous thermoplastic resin, and an acid-modified polymer, the showing in the specification employs one specific crystalline thermoplastic polymer, two specific amorphous thermoplastic resins, three specific acid-modified polymers, each contained within ranges not recited in the claim 1. While the non-obviousness of a genus can be supported by data showing unexpected results over a species or narrower range under certain circumstances, the burden is on the applicant to explain any proffered data. See MPEP 716 for discussion on overcoming obviousness-type rejections using unexpected results.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RAMSEY E ZACHARIA whose telephone number is (571)272-1518. The best time to reach the examiner is weekday mornings, Eastern time.
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/RAMSEY ZACHARIA/Primary Examiner, Art Unit 1787
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