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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/3/2026 and 3/2/2026 has been entered. Claim 1 is amended; claims 3-4 and 9 are cancelled; and claims 16-18 are added. Accordingly, claims 1-2, 5-8 and 10-18 are currently pending in the application.
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 § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 16 and 17 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Claims 16 and 17 recite “UV-stabilizer, a lubricant … talc, or combinations thereof” (lines 1-2). However, there is support only for the use of these additives alone and not as a combination of more than one (see paragraph 0027, wherein it states “additive streams 86 or 96 may include UV-stabilizers, lubricants, antioxidants, colorants, anti-statics, flame retardants and others. In one or more embodiments, these additives may include antioxidant or talc). A combination of two different additives (talc and antioxidant) may be added downstream of third separator (paragraph 0036) but not upstream of third separation vessel as recited in present claims.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 16 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 16 recites “”wherein the additive is added into separation system upstream of the third separation vessel via an additive stream” (lines 1-2) and fails to further limit the scope of independent claim 1 on which this claim is dependent. Specifically, additive as recited may be added in any location upstream of third separation and not necessarily limited to the addition of additive between second and third separation vessels as required by independent claim 1. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
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.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-2, 5-7 and 10-18 are rejected under 35 U.S.C. 103 as being unpatentable over Garland et al (US 2015/0011717 A1) in view of Kiss et al (US 2009/0076214 A1).
Regarding claims 1 and 6, Garland et al disclose a process for producing high pressure polyethylene (HPPE). The process includes contacting ethylene, an optional polar comonomer in the presence of an initiator to a reaction system under polymerization conditions to form a reaction system effluent comprising a first polyethylene resin having a first concentration of unreacted monomer and directing reaction system effluent to a pressure separation unit operated at separation conditions thereby removing at least a portion of the unreacted monomer from the reaction system effluent (abstract). HPPE resin can have a density as low as about 0.9 g/cm3 (paragraph 0010) which reads on LDPE in present claim 1. High pressure polymerization system 1 (Fig. 1) can include an ethylene feed source 3 that supplies ethylene monomer to a first compressor 5 that pressurizes the ethylene to a pressure of about 150 to 200 bar. A second compressor 10 located downstream of, and in fluid communication with the first compressor 5, increases the pressure of the reactor feed to greater than or equal to about 3000 bar (paragraph 0026) which reads on delivering a monomer feedstock comprising ethylene monomer to a compressor system to produce a pressurized feedstock having a pressure of at least 2000 bar in present claim 1. The compressed reactor feed is introduced to a reactor 18. The reactor can include two or more initiator injection points to feed initiator to the reactor 18 (paragraph 0028) to produce a polymer in combination with unreacted monomer (i.e., reads on passing the pressurized feedstock to at least one free radical polymerization reactor to produce a reactor effluent comprising LDPE and unreacted ethylene monomer in present claim 1). The exiting mixture of polymer alone or in combination with unreacted monomer can pass through a high pressure let down valve 32 into a separation system that can include one or more high pressure separation (HPS) vessels (i.e., reads on first separation vessel in present claim 1) and one or more low pressure separation vessels (paragraph 0029) which reads on second and third separation vessel in present claim 1. The low pressure separation vessel can operate at a pressure of from 0.5 bar to 2.0 bar (paragraph 0031) which overlaps with the operating pressure of second separation vessel in present claim 1. Case law holds that when the range of instant claims and that disclosed in prior art overlap, a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). See MPEP § 2144.05. It is noted that no stripping agents are added upstream of the separation vessel.
Garland et al are silent with respect to third separation vessel having an operating pressure of less than or equal to 0.05 bar; amount of unreacted monomer in separation product comprising LDPE; and adding additives.
Regarding third separation vessel having an operating pressure of less than or equal to 0.05 bar, Kiss et al in the same field of endeavor teach that polymer rich phase may be transferred to one or more low pressure separators running at just above atmospheric pressure for a simple flash of light components, reactants or oligomers for producing a low volatile-containing polymer melt entering the finishing extruder. Separators located downstream in the process operate at lower pressure relative to separators located upstream (paragraph 0255). The monomer rich phase is separated and recycled while the polymer rich phase is fed to a coupled devolatilizer (paragraph 0256). The devolatilization is a separation process to separate remaining volatiles (paragraph 0259) and devolatilizing device operates under a strong vacuum (paragraph 0273). Therefore, in light of the teachings in Kiss et al, it would have been obvious to one skilled in art prior to the filing of present application to include the devolatilizing device operating at low pressures of less than 0.05 bar (i.e., under vacuum), in the process of Garland et al, to remove any remaining volatiles including the unreacted monomers, absent evidence to the contrary.
Regarding amount of unreacted monomer in separation product comprising LDPE, given that the process of present claims is obvious based on the disclosure in Garland et al combined with the teachings in Kiss et al and includes a process wherein the separators located downstream operate at lower pressure relative to separators located upstream as in present invention, one skilled in art prior to the filing of present application would have a reasonable basis to expect the separation product comprising LDPE to include less than or equal to 50 ppm of unreacted ethylene monomer as in present claim 1 or less than 30 ppm as in present claim 6, absent evidence to the contrary. Since PTO cannot conduct experiments, the burden of proof is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding adding additives, Kiss et al teach that modifiers and additives may also be introduced either before or into the separator-blending vessel or downstream to it. However, a downstream introduction of these additives typically simplifies monomer recycle and is thus advantageous (paragraph 0150). Therefore, in light of the teachings in Kiss et al, it would have been obvious to one skilled in art prior to the filing of present application to add additives downstream including between the second and third separation vessel, for above mentioned advantages.
Regarding claim 2, Garland et al teach that purified polyethylene resin exiting the pressure separation unit is directed to a pelletization unit (paragraph 0005) which reads on pelletizing separation product without a subsequent purging step in present claim 2.
Regarding claim 5, Kiss et al teach that additives are added in amount of less than 1 wt% (paragraph 0087) which overlaps with the amount of additive in present claim 5.
Regarding claim 7, case law holds that differences in temperature will not support patentability of the subject matter encompassed by the prior art unless there is evidence indicating such temperature is critical. MPEP 2144.05. As such, temperature of the third separation vessel influences the removal of unreacted monomers by volatilizing and thus would be considered a result effective variable. Thus, it would have been obvious to one of ordinary skill in the art to have optimized the temperature to any range including 180 to 2600C through routine optimization.
Regarding claim 10, Kiss et al teach that there is a pressure letdown between the separators (paragraph 0151).
Regarding claims 11 and 12, Garland et al teach that high pressure polymerization system 1 (Fig. 1) can include an ethylene feed source 3 that supplies ethylene monomer to a first compressor 5 that pressurizes the ethylene to a pressure of about 150 to 200 bar. A second compressor 10 located downstream of, and in fluid communication with the first compressor 5, increases the pressure of the reactor feed to greater than or equal to about 3000 bar (paragraph 0026) which reads on compressor system comprises a primary compressor and secondary compressor in present claim 11 and pressure of the monomer feedstock to at least 200 bar prior to feeding to secondary compressor in present claim 12.
Regarding claim 13, Garland et al teach that reactor 18 can be a tubular or autoclave reactor (paragraph 0035).
Regarding claim 14, see figure 1, of Garland et al wherein there is a high pressure let down valve 32 located between the reactor and HPS (figure 1 and paragraph 0029) which reads on reactor effluent is passed to a letdown valve upstream of the separation system in present claim 14.
Regarding claim 15, Garland et al teach that HPPE resin can include polymer units derived from one or more polar monomers (paragraph 0019).
Regarding claims 16-18, examples of additives in Kiss et al include antioxidants, flame retardants, UV stabilizers, lubricating agents, and coloring agents (paragraph 0144). It is the Office’s position that it is within the scope of one skilled in art prior to the filing of present application to add additive via an additive stream as in present claim 16.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Garland et al (US 2015/0011717 A1) in view of Kiss et al (US 2009/0076214 A1) and Shin et al et al (US 2009/0076214 A1).
The discussion with respect to Garland et al and Kiss et al in paragraph 12 above is incorporated here by reference.
Garland et al and Kiss et al are silent with respect to operating pressure of the first separation vessel.
However, Shin et al disclose a method of recovering ethylene and vinyl comonomer that is capable of improving the rate of recovery of unreacted monomers. The method comprises polymerizing ethylene and vinyl based comonomer at a pressure of 1500 bar or more, a step of depressurizing the product obtained in the polymerization step including ethylene-vinyl based comonomer polymer, ethylene and comonomer (abstract). After the polymerization, the process of depressurizing to a pressure of 0.1 to 5 bar does not proceed all at once but is carried out sequentially undergoing the first depressurization step of reducing the pressure to 200 bar to 300 bar (i.e., reads on the operating pressure of first separation vessel in present claim 8), a second and third depressurizing step to 0.1 bar to 5 bar (paragraph 0017). The method for recovering in which the compression is progressed from respective pressures after separating them while lowering the pressure step by step reduces the cost required for the compression process, thus ensuring the economic efficiency of the process (paragraph 0018). Therefore, in light of the teachings in Shin et al, it would have been obvious to one skilled in art prior to the filing of present application, to use an operating pressure in the first separation vessel in overlapping ranges, in the process of Garland et al in view of Kiss et al independently, for above mentioned advantages.
Response to Arguments
The rejections under 35 U.S.C. 103 as set forth in paragraphs 8-10, of Office action mailed 11/3/2025, are withdrawn in view of amendments and/or applicant arguments and/or new grounds of rejection set forth in this Office action, necessitated by amendment.
While the grounds of rejection are changed, it was still deemed appropriate to address some of the arguments which would be pertinent to new grounds of rejection in this office action (See paragraph 15 below).
Applicant's arguments filed 2/3/2026 have been fully considered but they are not persuasive. Specifically, Applicant argues that (A) Garland low pressure separators operate at the same pressure, so there is no teaching to have a second separation vessel operating at a pressure from 1 to 5 bar and a downstream third separation vessel having an operating pressure of less than or equal to 0.05 bar; (B) Kiss does not teach that its devolatilizing device, which is cited for the third separation device, has an additive feed upstream, nor does it teach adding additives between the second separation vessel (1-5 bar pressure) and the third separation vessel (≤ 0.05 bar pressure). Kiss teaches that modifiers and additives may also be introduced either before or into the separator-blending vessel or downstream to it. A separator-blender is a high-pressure separator that operates at supercritical pressure conditions and also acts as a separator and a blender. This supercritical polymerization in Kiss may occur at 69-138 MPa (See paragraph [0018]), which equates to 690 to 1380 Bar. This is multiple magnitudes greater than both the second separation vessel (1-5 bar pressure) and the third separation vessel (≤ 0.05 bar pressure). Absent impermissible hindsight, Kiss's statement to add additives downstream of a high pressure-separator blender would not guide the skilled person to modify Garland to add additives between the recited second separation vessel (1-5 bar pressure) and third separation vessel (≤0.05 bar pressure) as claimed; and (C) skilled person would not have equated plasticizer with additives as claimed. In the present application, the additives may be antioxidants, UV-stabilizers, lubricants, antioxidants, colorants, antistatics, flame retardants and others. As defined in Garland, antioxidants are considered stabilizing agents. The present application similarly discusses that additives are used to stabilize the polymer produced, for example to "mitigate potential gel formation which is possible at vacuum pressures". The skilled person would not be guided to cure the deficiencies of Garland by consulting Kiss, because Kiss erroneously equates its plasticizers with the recited additives. The Kiss plasticizers are used for in-line blending with polyolefins to produce plasticized polymer blends. In contrast, the desired result of Garland is an LDPE polymer product, not a plasticized LDPE polymer blend that the hindsight reconstruction would yield. Thus, modifying Garland by the teachings of Kiss would result in a plasticized LDPE polymer blend which completely thwarts the desired result of Garland. Pursuant to MPEP 2143.01, a proposed modification is inappropriate when the modification renders the prior art reference inoperable for its intended purpose. As a result, there is no prima facie case of obviousness established over Garland in view of Kiss.
With respect to (A), Garland teach a process comprising using a high pressure polymerization system (Fig. 1) which can include an ethylene feed source that supplies ethylene monomer to a first compressor and a second compressor located downstream of, and in fluid communication with the first compressor, increases the pressure of the reactor feed to greater than or equal to about 3000 bar (paragraph 0026). The compressed reactor feed is introduced to a reactor to produce a polymer in combination with unreacted monomer. The exiting mixture of polymer in combination with unreacted monomer can pass through a high pressure let down valve into a separation system that can include one or more high pressure separation (HPS) vessels and one or more low pressure separation vessels. The low pressure separation vessel can operate at a pressure of from 0.5 bar to 2.0 bar. Graham v. Deere analysis was done and cited reference of Kiss et al teach that polymer rich phase may be transferred to one or more low pressure separators running at just above atmospheric pressure for a simple flash of light components, reactants or oligomers for producing a low volatile-containing polymer melt entering the finishing extruder. Separators located downstream in the process operate at lower pressure relative to separators located upstream (paragraph 0255). Hence, given that Garland et al are open to the inclusion of more than one separation vessels operating at lower pressure, it is the Office’s position that is within the scope of one skilled in art prior to the filing of present application to use a third separation vessel that is operated at a lower pressure than the second separation vessel based on the teachings in Kiss et al , absent evidence to the contrary.
With respect to (B) polymerization reactors in both Garland and Kiss operate at high pressures. Garland teaches using multiple separation devices to separate unreacted monomers from polymer. Kiss teaches that Separators located downstream in the process operate at lower pressure relative to separators located upstream. Modifiers and additives may be introduced either before or into the separator blending vessel or downstream to it. Examples of additives in Kiss et al include antioxidants, flame retardants, UV stabilizers, lubricating agents, and coloring agents (paragraph 0144). Hence, it is the Office’s position that it is within the scope of one skilled in art prior to the filing of present application to include additives in any location (such as between the second and third separation vessel as in present claims), absent evidence to the contrary. Case law holds that it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
With respect to (C), applicant attention is drawn to Kiss et al, wherein the additives listed include antioxidants, flame retardants, UV stabilizers, lubricating agents, and coloring agents (paragraph 0144). Kiss is only used for its teaching that downstream separators operate at a lower pressures preceding it and to include additives in the process.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KARUNA P REDDY whose telephone number is (571)272-6566. The examiner can normally be reached 8:30 AM to 5:00 PM M-F.
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/KARUNA P REDDY/
Primary Examiner, Art Unit 1764
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