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 .
DETAILED ACTION
Claims 1-17 of F.C. Rix et al. US 18/249,346 (04/17/2023) are pending, under examination on merits and are rejected.
Claim Interpretation
Examination requires claim terms first be construed in terms in the broadest reasonable manner during prosecution as is reasonably allowed in an effort to establish a clear record of what applicant intends to claim. See, MPEP § 2111. Under a broadest reasonable interpretation, words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. See MPEP § 2111.01. It is also appropriate to look to how the claim term is used in the prior art, which includes prior art patents, published applications, trade publications, and dictionaries. MPEP § 2111.01 (III).
The Subject Matter of Claims 1 and 16
Claim 1 is reproduced below:
1. A method comprising:
preparing an alumoxane precursor from an organic oxygen source, a hydrocarbyl aluminum, and an organic solvent;
heating the alumoxane precursor to form an alumoxane suspension;
removing solid methylaluminoxane from the alumoxane suspension by filtering the alumoxane suspension to form a filtered solution; and
combining the filtered solution with a support to form a supported alumoxane precursor.
Claim 16 is the same as claim 1 in additional to the claimed physical prosperities of the filtered solid methylaluminoxane.
The specification teaches that methylalumoxane, or MAO, is the most popular activator supported on silica to activate a single site catalyst precursor. Specification at page 2, [0005]. The specification teaches, however, that the actual structure of MAO is complicated and the while it is recognized to be a distribution of cage structures with a composition near Al1O0.75Me1.5 is when it is freshly prepared, the actual chemical structure of methylalumoxane (MAO) still remains uncertain. Specification at page 2, [0006].
The specification further teaches that MAO has peculiar, undesired gelation properties (that is upon standing, an unwanted gel may form from an MAO solution).
However, the MAO toluene solution is stored in a cold environment, e.g., at -20 to -30°C, to reduce the gelation process typically observed for this kinetic product. A homogeneous MAO solution is desired for MAO molecules to be evenly distributed in the pores of the catalyst support material, e.g., silica, to obtain a catalyst with good performance including good productivity and good operability.
Specification at page 2, [0005]. Per the above specification portion, the solid gel is unwanted because homogenous solutions of MAO are desired when mixing with a support so as to evenly distribute the soluble MAO in the support’s pores (the solid MAO having been removed). It appears from the specification that soluble MAO is of a different structure than the insoluble, gelled MAO. The specification refers the soluble MAO as non-hydrolytic methylaluminoxane (NH-MAO). Specification at page 4, [0018]
Thus, the gist of the claimed invention is preparing an alumoxane solution using an organic oxygen source, where the solid or gelled MAO is first removed by filtration (and where the solid/gelled MAO is a different structure than the solubilized MAO), and then the filtered solution is used to impregnate the support, so that (in the absence of the solid/gelled MAO) the solubilized MAO molecules are more evenly distributed in the pores of the catalyst support material.
The specification evidences the improvement in a supported catalyst prepared from filtered solution of MAO (where the different solid/gelled MAO is removed) versus a supported catalyst prepared from an unfiltered solution. That is per specification Table 1, the productivity of the catalyst 3b prepared with a filtered MAO solution is - better than that of the catalyst comp 2 prepared with an non-filtered MAO solution (7975 gPgcat-1hr-1 vs 332 gPgcat-1hr-1). Specification at page 20, Table 1.
It should be noted that the specification does not disclose any specific utility of the solid achieved through filtration in the claimed method, therefore, the physical particle limitations in claims 2 and 16 are limiting a byproduct which is no utility in the claimed invention.
Interpretation of the term “alumoxane” and “methylaluminoxane”
The independent claim 1 and claim 16 recite the term of “alumoxane” as follows:
A method comprising:
preparing an alumoxane precursor from an organic oxygen source, a hydrocarbyl aluminum, and an organic solvent;
heating the alumoxane precursor to form an alumoxane suspension; removing solid methylaluminoxane from the alumoxane suspension by filtering the alumoxane suspension to form a filtered solution; and
combining the filtered solution with a support to form a supported alumoxane precursor.
The specification does not provide any definition to the term of “alumoxane”.
Bergsma teaches that:
Aluminoxanes (also sometimes referred to as alumoxanes) may be linear, cyclic, oligomeric or polymeric structures wherein two or more aluminum atoms are linked via an oxygen bridge. For example, they have structures like R(-AI(-R)-O)n-AI-R2, wherein n is an integer, each R can independently be an alkyl or alkoxy group, and optionally two or more of the R groups may be linked together to give the indicated cyclic structures, i.e., two R groups can be an oxygen bridge between two aluminium atoms.
J. M. Bergsma, et al, WO2016170017A1 (2016)(“Bergsma”), page 1, line 9-15.
Therefore, according to the prior art, the term of “alumoxane” is broadly and reasonably interpreted as any oligomeric or polymeric compound represented by the formula of R(-AI(-R)-O)n-AI-R2, wherein n is an integer, each R independently selected from an alkyl or alkoxy group.
Regarding the claimed “methylaluminoxane”, the information disclosed by the specification as follows:
[0004] Methylaluminoxane (MAO), sometimes referred to as polymethylaluminoxane (µMAO) . . .
. . . .
[0006] MAO is typically formed from the low temperature reaction of trimethylaluminum (TMA) and water in toluene. This reaction is very exothermic and requires special care to control. MAO is recognized to be a distribution of cage structures with a composition near Al1O0.75Me1.5 when it is freshly prepared.
Specification at page 1-2, [0004]-[0006], emphasis added.
According to the information disclosed by the specification, the term “methylaluminoxane” is broadly and reasonably interpreted as any compound having a composition Al1O0.75Me1.5.
Interpretation of the term “organic oxygen source”
The independent claim 1 and claim 16 recite the term of “organic oxygen source” as follows:
A method comprising:
preparing an alumoxane precursor from an organic oxygen source, a hydrocarbyl aluminum, and an organic solvent;
heating the alumoxane precursor to form an alumoxane suspension; removing solid methylaluminoxane from the alumoxane suspension by filtering the alumoxane suspension to form a filtered solution; and
combining the filtered solution with a support to form a supported alumoxane precursor.
The specification does not provide any definition to the term of “organic oxygen source”, the specification disclose the following open-side discussion related to the claimed “organic oxygen source”:
[0007] MAO has also been prepared by reaction of TMA and organic oxygen sources such as carbon dioxide (US 5,831,109; US 5,777,143), benzoic acid (US 5,831,109, US 6,013,820; US 7,910,764 B2; US 8,404,880 B2; Dalet, T. et. al. (2004).
And
[0025] In the method, the organic oxygen source can be methacrylic acid, the organic solvent is an alkane solvent, and the hydrocarbyl aluminum is trimethylaluminum.
Specification at page 2, [0007] and page 4,[0025], emphasis added.
According to its plain meaning and consistent with the specification, the term of “organic oxygen source” is broadly and reasonably interpreted as any compound comprising at least one carbon atom and at least one oxygen atom.
Withdrawal Claim Rejections - 35 USC § 112(b)
Rejection of claims 1-3 and 5-13, 16-17 are rejected under 35 U.S.C. 112(b) as indefinite is withdrawn in view of the instant claim 1 and 16 have been amended by further limitation of the claimed hydrocarbyl aluminum must comprise trimethylaluminum.
Maintained Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Pursuant to 35 U.S.C. 112(b), the claim must apprise one of ordinary skill in the art of its scope so as to provide clear warning to others as to what constitutes infringement. MPEP 2173.02(II); Solomon v. Kimberly-Clark Corp., 216 F.3d 1372, 1379, 55 USPQ2d 1279, 1283 (Fed. Cir. 2000). The meaning of every term used in a claim should be apparent from the prior art or from the specification and drawings at the time the application is filed. Claim language may not be ambiguous, vague, incoherent, opaque, or otherwise unclear in describing and defining the claimed invention. MPEP § 2173.05(a).
Unclear Relationship in the Units of “gP/gcat-1 hr-1”
Rejection of claim 14 under 35 U.S.C. 112(b) as indefinite because the unit of “gP/gcat-1 hr-1” is not clear.
The plain meaning of the unit “gcat” is the weight of a catalyst. Given there are at least two catalyst compounds (supported methylaluminoxane and one or more catalyst compounds) in the instant claim 10, it is not clear the catalyst in the unit of gP/gcat-1 hr-1 is the supported methylaluminoxane, the one or more catalyst compounds, or their combination?
Maintained Claim Rejections - 35 USC § 103
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.
35 USC § 103 Rejection over Kamfjord, Bergsma and Wang
Rejection of claims 1-11 and 13-17 under 35 U.S.C. 103 as being unpatentable over the combination of J. M. Bergsma, WO2016170017A1 (2016)(“Bergsma”) with T. Kamfjord, et al, 19 Macromolecular rapid communications 505-509 (1998)(“Kamfjord”) in view of H. Wang, et al, In IOP Conference Series: Materials Science and Engineering (Vol. 362, No. 1, p. 012023). IOP Publishing (2018)(“Wang”) is maintained for the same reason as given in the previous Office action and is repeated as below.
J. M. Bergsma, WO2016170017A1 (2016)(“Bergsma”)
Bergsma teaches:
Aluminoxanes are known in the industry, mainly by their application as a catalyst component in polymerization catalysts, especially as a co-catalyst in metallocene catalysts that are used in polymerizing or oligomerizing olefins.
Aluminoxanes (also sometimes referred to as alumoxanes) may be linear, cyclic, oligomeric or polymeric structures wherein two or more aluminium atoms are linked via an oxygen bridge. For example, they have structures like R(-AI(-R)- O)n-AI-R2, wherein n is an integer, each R can independently be an alkyl or alkoxy group, and optionally two or more of the R groups may be linked together to give the indicated cyclic structures, i.e., two R groups can be an oxygen bridge between two aluminium atoms. When at least part of the R groups are methyl groups, the aluminoxane is called a methylaluminoxane (MAO).
Bergsma at page 1, line 5-17, emphasis added.
Bergsma teaches that methylaluminoxane can be prepared through a reaction of trimethylaluminium with water in an organic solvent. Bergsma at page 2, line 1-2.
Bergsma teaches that:
the reaction between water and trimethylaluminium not only gives the desired aluminoxanes but is also known to give some aluminium salts, like aluminium hydroxide and aluminium oxides, that will precipitate, and gel formation.
Bergsma at page 2, line 11-15, emphasis added.
Bergsma teaches a method preparing of alkylaluminoxanes by reaction of alkylaluminium with methacrylic acid, or a conjugated unsaturated carbonyl- functional compound, in a ratio of 0.1 to 0.8 molar equivalent oxygen atoms in the part -C=O(R4) of the methacrylic acid or conjugated unsaturated carbonyl-functional compound to 1 equivalent of aluminium atoms in the alkylaluminium reactant, and in the presence of an inert organic solvent. Bergsma at page 2, line 21 to page 3, line 9, emphasis added.
Bergsma teaches that:
The inert organic solvent in which the process of the present invention is performed can be any organic hydrocarbon solvent that the skilled person knows is not reactive with an alkylaluminium compound. Examples thereof are alkanes, such as heptanes, hexanes, or aromates, such as toluene, xylene, ethylbenzene, cumene, mesitylene.
Bergsma at page 10, line 10-14, emphasis added. Bergsma teaches that:
The invention in addition provides the alkylaluminoxanes obtainable by the above process and their use as a component in catalysts used for olefin polymerization or oligomerization processes, such as processes to prepare polyethylene, polypropylene, or rubber. The catalyst in which aluminoxane is used can be a homogeneous or heterogeneous catalyst with or without a support or carrier.
Bergsma at page 3, line 11-16, emphasis added. Bergsma also teaches that the support can be silica. Bergsma at page 10, line 28. Furthermore, Bergsma teaches that:
In yet another preferred embodiment of the processes of the invention, in a first step the methacrylic acid or conjugated unsaturated carbonyl-functional compound is dosed to a trialkylaluminium solution in inert solvent, which is next dosed to a suspension of inert solvent optionally containing a carrier, after which further alkylaluminium is added and the resulting reaction mixture (suspension) undergoes a heat treatment.
Bergsma at page 8, line 23-28. Thus, Bergsma fairly teaches that a solution of alkylaluminoxanes can be combined with a support to form a supported alkylaluminoxanes precursor.
Bergsma teaches working example of the method such as example 6:
Example 6
2- methylpropenoic acid (methacrylic acid) as reactant
A 30 ml glass vial equipped with a magnetic stirring bar was charged with 8.5 g toluene and 2.70 g (37.5 mmol) trimethylaluminium (ex AkzoNobel). To this solution, 0.65 g (7.5 mmol) of 2-methylpropenoic acid (ex Sigma-Aldrich) was slowly added, resulting in an exothermic reaction with gas formation.
1H-NMR analysis of the reaction product after dosing showed multiple peaks in the Al-Me region, which is indicative of the presence of intermediate products. The reaction mixture was left to stir at room temperature for 20 hours.
The mixture was then heated to 105°C (oil bath) for 1 hour.
1H-NMR analysis showed that the intermediate peaks disappeared and showed the formation of a broad signal next to the TMAL peak, confirming methylaluminoxane formation.
Bergsma at page 14, Example 6, emphasis added.
It should be noted that the Bergsma example 6 method is substantially the same method as that of working Example 2 of the specification except Bergsma dose not teach to cool the reaction mixture to room temperature over three days and filtration.
To summarize, Bergsma teaches:
(i).preparing an alumoxane precursor from an organic oxygen source which is 2-methylpropenoic acid, a hydrocarbyl aluminum which is trimethylaluminium , and an organic solvent which is toluene;
(ii). heating the alumoxane precursor;
(iii).combining of a solution of alkylaluminoxanes with a support to form a supported alkylaluminoxanes precursor.
T. Kamfjord, et al, 19 Macromolecular rapid communications 505-509 (1998)(“Kamfjord”)
Kamfjord teaches that:
The heterogenization of metallocene/MAO1 catalysts is industrial practice for three reasons: 1) to improve polymer morphology, 2) to reduce reactor fouling and 3) to reduce the amount of MAO. Usually the metallocene is deposited on the support from a solution. MAO and/or alkylaluminum is codeposited on the support or added separately.
Kamfjord at page 505, line 1-7. Kamfjord teaches a method for preparation of metallocene/MAO catalysts as follows:
Catalyst synthesis
Both MAO and metallocene were added to the support according to the “incipient wetness” method), i. e. only enough liquid was used to just fill the pores of the silica.
Support: 30 wt.-% MAO in toluene (7mL) was added dropwise to silica (2 g) at 20°C and stirred. The toluene was removed by evacuation to give silica with 49.1 wt.-% MAO.
Catalyst M: (BuCp)2ZrCl2 (0.0076 g/0.019 mmol) dissolved in toluene (3 mL) was added to the support (2 g) at 20°C. Toluene was removed by evacuation (2 h).
Catalyst H1, S1, S2 and O: (BuCp)2ZrClz (0.0076g/0.019 mmol) dissolved in 1-hexene (catalyst H1, 3 mL/24 mmol), styrene (catalyst S1l, 3 mL/26 mmol) or 1,7-octadiene (catalyst O, 3 mL/20 mmol) was added to the support (2 g) at -50°C, -30°C or -50°C, respectively. The mixture was brought to 25°C overnight, allowing the liquid monomer to polymerize slowly. Catalyst S2 was prepared as catalyst S1, however the support was impregnated with a solution of 0.024 g/0.06 mmol (BuCp)2Cl2 in 3 mL/26 mmol styrene.
Kamfjord at page 505-506, Catalyst synthesis, ld, emphasis added.
Kamfjord also conducted an ethene polymerization with the prepared metallocene/MAO catalysts; and teaches that catalyst containing polystyrene (S1) is remarkably more active than the other catalysts. Kamfjord at page 507,Table 2, Fig. 2 and left col. line 1-3 under Fig.2.
Therefore, Kamfjord teaches:
(i). form an alumoxane solution which is a solution of MAO in toluene;
(ii). combining the solution with a support which is silica to form a supported alumoxane precursor;
(iii).drying the supported alumoxane precursor to form a supported alumoxane;
(iv).generating a catalyst system by introducing one or more catalyst compounds which is (BuCp)2ZrCl2 to the supported alumoxane precursor.
One ordinary skilled artisan seeking metallocene/MAO catalysts for ethene polymerization is motivated to use the method such as Example 6 taught by Bergsma to prepare methylaluminoxane (MAO) and then utilize the prepared methylaluminoxane to prepare a metallocene/MAO catalyst as taught by Kamfjord, resulting a method comprising:
(i).preparing a MAO precursor from 2-methylpropenoic acid, trimethylaluminium , and toluene;
(ii). heating the MAO precursor;
(iii). form a solution of MAO in toluene;
(iv). combining the solution with a support which is silica to form a supported MAO precursor;
(v). drying the supported MAO precursor to form a supported MAO precursor; and
(vi). generating a catalyst system by introducing (BuCp)2ZrCl2 to the supported MAO precursor.
Difference between the Combined method and the Claims
The combination of Bergsma and Kamfjord differs the instant claim 1 and 16 in that neither Bergsma nor Kamfjord teaches to removing solid methylaluminoxane from a solution of methylaluminoxanein toluene by filtering a methylaluminoxane suspension.
H. Wang, et al, In IOP Conference Series: Materials Science and Engineering (Vol. 362, No. 1, p. 012023). IOP Publishing (2018)(“Wang”).
Wang tested the water content in toluene of chemical reagents collected from 48 laboratories from 18 provinces/cities/municipals and teaches that the water content in toluene is 300.5 mg/kg-717.0 mg/kg, with a mean value of 395.3 mg/kg (0.0395%). Wang at Title, Abstract and Table 2 at page 4.
Obvious Rational of the Claims 1-11 and 13-17
It would have been prima facie obvious for one skilled artisan to arrive at the instantly claimed invention based on the teachings from Kamfjord, Bergsma and Wang with a reasonable expectation of success before the effective filing date of the claimed invention.
One ordinary skilled artisan seeking metallocene/MAO catalysts for ethene polymerization is motivated to modified the combined method above by including the steps of :
(i). Cooling the Bergsma Example 6 reaction mixture to a suspension mixture;
(ii). filtering the suspension mixture to form a filtered solution of methylaluminoxane in toluene;
(iii) use the filtered solution of methylaluminoxane in toluene to prepare a metallocene/MAO catalyst as taught by Kamfjord.
Thus, arriving at a method meeting each and every limitation of claims 1 and 4, therefore, claims 1 and 4 are obvious. One ordinary skilled artisan has a motivation to do so with a reasonable expectation of success because:
(i). Wang teaches that there is about 0.0395% of water in toluene; Wang Table 2 at page 4.
(ii). Bergsma teaches that water in toluene can reacts with trimethylaluminium to give gives methylaluminoxane and aluminium salts, like aluminium hydroxide and aluminium oxides, that will precipitate, and gel formation;
Therefore, one ordinary skilled artisan knows a precipitation/ gel would be formed in the reaction mixture and has a motivation to remove the precipitation/ gel by filtering as removing of the precipitation/gel comprising of aluminium salts and methylaluminoxane can remove the by-products, which would increase the catalytic activity of methylaluminoxane.
The rational supporting the proposed method is combining prior art elements according to known methods to yield predictable results. MPEP 2134.I.(A).
Claims 2 and 16 recite the following physical limitations for the unwanted, gelled/solid methylaluminoxane (MAO) particles removed by filtration:
Claims 2 and 16The method of claim 1, wherein the filtering the alumoxane solution comprises filtering the solid methylaluminoxane having one or more of the following properties:
a particle size distribution of from about 30 μm to about 45 μm (<10%),
from about 50 μm to about 70 μm (<25%),
from about 110 μm to about 140 μm (<50%),
from about 390 μm to about 420 μm (<75%), or
from about 820 μm to about 840 μm (<90%);
a BET Surface area of from about 10 m2/g to about 80 m2/g; and/or
a pore volume of from about 0.01 mL/g to about 0.2 mL/g (BJH adsorption cumulative between 17 Å and 3000 Å).
These limitations are met by the cited art for the following reasons. Bergsma example 6 method is substantially the same method as that of working Example 2 of the specification, there is a reasonable expectation that the same method would form the same products including the physical properties of the by-products and the ratio between the by product and desired product. Thus, filtering the Bergsma solution, as proposed, gives the same solid particles having the same claim 8 and 16 physical limitations. Once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of production shifts to the applicant. MPEP § 2112(V) (citing In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 (CCPA 1977).
Claim 3 is obvious because the proposed method comprises drying the supported MAO precursor to form a supported MAO precursor.
Claim 5 is obvious because Bergsma teaches that in the Example 6 the ratio between 2-methylpropenoic acid (7.5 mmol) and trimethylaluminium (37.5 mmol) is 1:5.
Claim 6 is obvious because one ordinary skilled artisan is further motivated to modify the proposed method by adding a solution of 2-methylpropenoic acid in toluene dropwise into the solution of trimethylaluminium in toluene so that can make the reaction take place at a mild condition because Bergsma teaches that the reaction between 2-methylpropenoic acid and trimethylaluminium is an exothermic reaction; and the addition of 2-methylpropenoic acid needs to be slowly.
Claim 7 is obvious because Bergsma teaches that the heating temperature in the Example 6 is 105ºC.
Claim 8 recites as follows:
8. (Currently Amended) The method of claim 1, wherein the alumoxane suspension comprises from about 2 wt% to about 4 wt% of the solid methylaluminoxane and about 96 wt% to about 98 wt% of a solvent mixture comprising nonhydrolytic methylaluminoxane (NH-MAO).
The limitations of claim 8 are met by the proposed obviousness rational for the same reasons discussed above for particles size limitations of claims 2 and 16. Bergsma example 6 method is substantially the same method as that of working Example 2 of the specification, there is a reasonable expectation that the same method would form the same products in the same wt%. Once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of production shifts to the applicant. MPEP § 2112(V) (citing In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 (CCPA 1977).
Claim 9 is obvious because one ordinary skilled artisan is motivated to cool the Example 6 reaction to room temperature before filtration so that can make more sold to be precipitated and make sure the filtration to be conducted at a safe condition .
Claims 10-11 and 13 are obvious because the proposed method comprises generating a silica supported (BuCp)2ZrCl2 /MAO catalyst; and one ordinary skilled artisan is motivated to use the catalyst for ethene polymerization as taught by Kamfjord.
Claim 14 is obvious for the same reasons as claims 2, 8, and 16. Also see § 112(b) rejection of claim 14 above. Practice of Bergsma example 6 with Kamfjord as proposed above results in a method is substantially the same method as that of working Example 3b of the specification except a different homologues2 of the metal catalyst are used [(BuCp)2ZrCl2 vs (1,3-Me BuCp)2ZrCl2], there is a reasonable expectation that upon filtering the Bergsma MAO mixture and generating a silica supported(BuCp)2ZrCl2 /MAO as taught by Kamfjord as proposed would arrive at a similar catalyst as 3b in the specification, the similar catalyst would result having the similar catalyst activity. Once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of production shifts to the applicant. MPEP § 2112(V) (citing In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 (CCPA 1977). In this regard, Kamfjord teaches that the catalyst S1 has a catalytic activity of 491 Kg PE/(mol Zr•h) in run No. 18, which is 491000 g PE/(91 g Zr•h)=5,395 g PE/(g Zr•h) that anticipates the claimed 3,000 g/g to 20,000/g/g. See Kamfjord at page 507, Table 2.
Claim 15 is obvious because one ordinary skilled artisan is also motivated to modify the proposed method by replacing toluene with an alkane such as heptane because Bergsma teaches that alkanes such as heptane can be used as the solvent.
Claim 17 is obvious because one ordinary skilled artisan is also motivated to further isolate methylaluminoxane from the filtered solid comprising methylaluminoxane and aluminum slats, and then use it with one or more catalyst to generate a polymer because Bergsma teaches that aluminoxanes are known in the industry as a co-catalyst component in polymerization catalysts. Bergsma at page 1, line 5-7.
Applicant’s Arguments
Applicant first argues on the ground that the "solid methylaluminoxane" removed during the filtering step is not a byproduct of water contamination because 1HNMR analysis of the solid (Figure 1) clearly demonstrates the characteristic signals of methylaluminoxane. Page 6, I. Identity of the Solids: Active MAO vs. Inert Impurities, of the Remarks filed on 01/09/2026.
This argument has been fully considered but not persuasive. As mentioned in the 103 rejection made in the previous Office action that Bergsma teaches that the solid is a mixture of methylaluminoxane and aluminium salts, like aluminium hydroxide and aluminium oxides. 1HNMR signals of methylaluminoxane cannot exclude there is aluminium salts such as aluminium hydroxide and aluminium oxides because it is hard to get strong signals for aluminium salts such as aluminium hydroxide and aluminium oxides in 1HNMR analysis.
Applicant further argues on the ground that:
Kamfjord teaches that the primary reasons for heterogenization (supporting catalysts) are to improve polymer morphology and reduce reactor fouling (Kamfjord at page 505). However, the combination of Bergsma and Kamfjord fails to achieve these goals.
Page 7, II. Physical Exclusion and the Failure of the Combined Teachings, of the Remarks filed on 01/09/2026.
This argument is not persuasive, as mentioned in the 103 rejection made in the previous Office action that Kamfjord teaches three reasons for heterogenization of methylaluminoxane : 1) to improve polymer morphology, 2) to reduce reactor fouling and 3) to reduce the amount of MAO. The proposed method is first filtration of the Bergsma Example 6 and then supported the filtration on the Kamfjord support. Applicant does not provide any evidence to show the combination fails to achieve these goals taught by Kamfjord, or the motivation is lacks for the proposed modification.
Applicant’s Argument Regarding Unexpected Results
Applicant argues that Applicants have surprisingly found that the highest activity species (the solid MAO) is actually detrimental to reactor performance; and by removing solid MAO from an alumoxane suspension, homogeneous supported alumoxanes can be obtained with good activity and which minimize reactor fouling. Page 7-8, III. Unexpected Results, of the Remarks filed on 01/09/2026.
Relevant Sections of the MPEP
A greater than expected result and evidence of unobvious or unexpected advantageous properties are evidentiary factors pertinent to the legal conclusion of obviousness of the claims at issue. MPEP § 716.02(a)(I)/(II). However, the burden is on Applicant to establish that the evidence relied upon demonstrates that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance. MPEP § 716.02(b). Evidence of unexpected properties may be in the form of a direct or indirect comparison of the claimed invention with the closest prior art which is commensurate in scope with the claims. MPEP § 716.02(b)(III).
Furthermore, whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support; that is, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. MPEP § 716.02(d). The nonobviousness of a broader claimed range can be supported by evidence based on unexpected results from testing a narrower range if one of ordinary skill in the art would be able to determine a trend in the exemplified data which would allow the artisan to reasonably extend the probative value thereof. MPEP § 716.02(d)(I).
Further, an affidavit or declaration under 37 CFR 1.132 also must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. MPEP § 716.02(e).
The Results Proffered in the Specification
The instant application discloses the comparative results as shown in the Table 1 of the specification as indicated below.
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564
774
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Specification at page 20, Table 1.
The Proffered Results Do Not Overcome the § 103 Rejection Because Applicant Has Not Met Its Burden of Demonstrating that the Proffered Result Is Unexpected
It is not unexpected that productivity difference between Comp 1-2 and the Ex 1b-10 because there is no heating for preparation of the “methylaluminoxane” used for the Comp 1-2 (See Comparative 1-2 of the specification at page 14-15) while there is heating at 105 ºC for 2 hs for the “methylaluminoxane” used for the Ex1b-10 (See Comparative 2a and Example 2 of the specification at page 15-16). Thus, Comp 1-2 do not comprise the similar amount of methylaluminoxane as those of Ex 1b-10, it is expected that the catalytic activities of Comp 1-2 is lower than that of Ex 1b-10.
Catalyst system Ex 1b-1d prepared with unfiltered reaction mixture from Comparative 2a has a catalytic activity of 6630-13484 gP/(gcat. hr); Catalyst system Ex 3b-10 prepared with filtration from Example 2 has a catalytic activity of 2025-19092 gP/(gcat.hr); Applicant has provided no explanation of how this catalytic activity difference is unexpected and unobvious and of both statistical and practical significance. MPEP § 716.02(b). Applicant has therefore not met its burden. MPEP § 716.02(b). The burden is on Applicant to establish that the evidence relied upon demonstrates that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance. MPEP § 716.02(b).
With regarding Applicant argues that solid MAO has extreme productivity (19,092 g/g/h) and cause reactor fouling; while examples 3b, 4b, 4c, 5b, and 5c has high productivity (3,000-8,000 g/g/h) and zero reactor fouling. This argument is not persuasive because:
(1). examples 3b, 4b, 4c, 5b, and 5c has additional catalyst compound that is (1,3-Me, BuCp)2ZrCl2, therefore, it is expected to have higher productivity; and
(2). As mentioned in the rejection that Kamfjord teaches that heterogenization of methylaluminoxane can reduce reactor fouling; examples 3b, 4b, 4c, 5b, and 5c are all heterogenous catalyst system, therefore, it is expected to have less fouling in the reactor.
The Proffered Results Do Not Overcome the § 103 Rejection Because the Proffered Results are Not Commensurate in Scope with the Claims
Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support; that is, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. MPEP § 716.02(d). Herein, all the comparative catalyst is prepared by reacting of trimethylaluminum with the same organic oxygen source that is methacrylic acid, which is clearly not commensurate in scope with the large genera of organic oxygen source claimed by the claim 1 and/or 16.
35 USC § 103 Rejection over Casagrande, Bergsma and Wang
Rejection of claims 1-10 and 12-13, 15-17 under 35 U.S.C. 103 as being unpatentable over the combination of J. M. Bergsma, WO2016170017A1 (2016)(“Bergsma”) with A.C. Casagrande, et al, 255 Journal of Molecular Catalysis A: Chemical 19-24 (2006)(“Casagrande”) in view of H. Wang, et al, In IOP Conference Series: Materials Science and Engineering (Vol. 362, No. 1, p. 012023). IOP Publishing (2018)(“Wang”) is maintained for the same reason as given in the previous Office action and is repeated as below.
J. M. Bergsma, WO2016170017A1 (2016)(“Bergsma”)
Bergsma has been discussed above.
A.C. Casagrande, et al, 255 Journal of Molecular Catalysis A: Chemical 19-24 (2006)(“Casagrande”).
Casagrande teaches that:
The catalyst precursors TpMs*V(L)Cl2 [1,L=NtBu; 2, L = O; TpMs* = (3-mesityl-pirazolyl)2(5-mesityl-pirazolyl)] were in situ supported onto SiO2 and onto methylaluminoxane (SMAO-4) and trimethylaluminum (STMA-3) modified silicas using 0.02 wt.% V/support. All catalyst systems were shown to be active in ethylene polymerization.
Casagrande at Abstract, emphasis added. Per table 2, Casagrande teaches that with MAO as the co-catalyst, catalyst precursor TpMs*V(NtBu)Cl2 (1) on methylaluminoxane modified silica(SMAO-4) has the best catalytic activities [1900 (kg PE/mol [V] h atm] for ethylene polymerization. Casagrande at page 21, table 2.
Casagrande teaches that TpMs*V(NtBu)Cl2 (1) is an non-metallocene catalyst precursors. Casagrande at page 19, line 12-13.
Regarding the preparation of the TpMs*V(NtBu)Cl2 (1) on methylaluminoxane modified silica(SMAO-4) catalyst, Casagrande teaches that:
2.2. Preparation of SiO2/MAO (4.0 wt.% Al/SiO2)
MAO-modified silica was prepared by impregnating 1.0 g of previously thermally activated silica with a MAO toluene solution (0.9 mL) at room temperature for 3 h under stirring. The solvent was removed under vacuum and the solid was dried. The resulting solid was named SMAO-4.
. . .
2.4. In situ supported non-metallocene catalyst
TpMs*V(NtBu)Cl2 (1) or TpMs*V(O)Cl2 (2) was directly added to support within the polymerization reactor in presence of cocatalyst.
Casagrande at page 20, Experimental, 2.2-2.4, emphasis added.
Thus, Casagrande teaches:
(i). form an alumoxane solution which is a solution of MAO in toluene;
(ii). combining the solution with a support which is silica to form a supported alumoxane precursor;
(iii). drying the supported alumoxane precursor to form a supported alumoxane;
(iv). generating a catalyst system by introducing one or more catalyst compounds which is TpMs*V(NtBu)Cl2 (1) to the supported alumoxane precursor.
One ordinary skilled artisan seeking catalysts for ethene polymerization is motivated to use the method such as Example 6 taught by Bergsma to prepare methylaluminoxane (MAO) and then utilize the prepared methylaluminoxane to prepare a TpMs*V(NtBu)Cl2 /SMAO-4 as taught by Casagrande, resulting a method comprising:
(i).preparing a MAO precursor from 2-methylpropenoic acid, trimethylaluminium , and toluene;
(ii). heating the MAO precursor;
(iii). form a solution of MAO in toluene;
(iv). combining the solution with a support which is silica to form a supported MAO precursor;
(v). drying the supported MAO precursor to form a supported MAO precursor; and
(vi). generating a catalyst system by introducing TpMs*V(NtBu)Cl2 to the supported MAO precursor.
Difference between the Combined method and the Claims
The combination of Bergsma and Casagrande differs the instant claim 1 and 16 only in that neither Bergsma nor Casagrande teaches to removing solid methylaluminoxane from a solution of methylaluminoxanein toluene by filtering a methylaluminoxane suspension.
H. Wang, et al, In IOP Conference Series: Materials Science and Engineering (Vol. 362, No. 1, p. 012023). IOP Publishing (2018)(“Wang”).
Wang has been discussed above
Obvious Rational of the Claims 1-10 and 12-13, 15-17
It would have been prima facie obvious for one skilled artisan to arrive at the instantly claimed invention based on the teachings from Casagrande, Bergsma and Wang with a reasonable expectation of success before the effective filing date of the claimed invention.
Claims 1-10 and 13, 15-17 are obvious for the same reasons as given above.
Claim 12 is obvious because the Casagrande catalyst precursor TpMs*V(NtBu)Cl2 (1) in the TpMs*V(NtBu)Cl2/SMAO-4 is an non-metallocene catalyst precursors.
Applicant’s Arguments
Applicant’s argument on the filtered solid is not by product has been addressed above.
Applicant further argues on the particle size of the filtered solid. Paragraph 6-7 at page 9 of the Remarks filed on 01/09/2026. This argument is not persuasive. As mentioned in the rejection that Bergsma example 6 method is substantially the same method as that of working Example 2 of the specification, there is a reasonable expectation that the same method would form the same products including the physical properties of the by-products. Thus, filtering the Bergsma solution, as proposed, gives the same solid particles having the same physical limitations. Once a reference teaching product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of production shifts to the applicant. MPEP § 2112(V) (citing In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 (CCPA 1977).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/FRANK S. HOU/Examiner, Art Unit 1692
/ALEXANDER R PAGANO/Primary Examiner, Art Unit 1692
1Methylaluminoxane see Kamfjord at page 505, Chemicals.
2 Compounds which are homologs (compounds differing regularly by the successive addition of the same chemical group, e.g., by -CH2- groups) are generally of sufficiently close structural similarity that there is a presumed expectation that such compounds possess similar properties. MPEP 2144.09.II.