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 .
Claim Status
The claims are newly amended.
Response to Arguments
Applicant's arguments filed 1/22/26 have been fully considered but they are not persuasive.
The remarks argue on page 6, the following:
In the remarks presented in the Office Action for claim 1, the Examiner does not address the limitation regarding the disagglomeration rate as required by the claims, specifically claim1 which recites a disagglomeration rate a equal to or greater than 0.5x10-2m- Rather, theExaminer addresses the limitation by referring to dependent claims 7-11 (though. However, since the disagglomeration rate limitation is present within claim 1, Allain is addressed here.
The remarks are respectfully considered here. The feature claimed describing the disagglomeration rate in the claim is explained in the specification at paragraph 29 of the published specification as the precipitated silica’s ability to disperse in an elastomeric composition. However, since the composition is the same, the same composition would have the same characteristics.
Next, the remarks argue the following:
Allain teaches a process for precipitating silica. The process of preparing the silica involves first acidifying silicate, followed by increasing the pH of the solution using an alkaline agent.
The product formed has a CTAB of 60-400 m2/g and undergoes a deagglomeration test. As to the deagglomeration speed/rate, denoted a, this is measured using certain device useable to measure the evolution of the average size of the particle agglomerates. The deagglomeration rate is at least 0.02pm- The characteristics of this precipitated silica have improved hysteresis and reinforcementproperties. As such, the Examiner alleges that it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain a precipitated silica with a deagglomerate rate of 0.02 pm1 min-1, as taught by Allain for use with the precipitated silica of Valero and Jacques because this property is known to improve hysteresis and reinforcement properties of the precipitated silica. Applicant respectfully disagrees.
The present claims are directed to precipitated silicas that are characterized by a specific combination of properties. Furthermore, the present precipitated silicas are prepared such that the pH of the precipitated silica is less than 5.5. In the specification as filed, Applicant has demonstrated that when the pH of the precipitated silica is below 5.5, a disagglomeration rate a equal to or greater than 0.5x10-2m-min-1 may be obtained. The Examples of the specification as filed also demonstrate that when compared to precipitated silicas formed with pH values higher than 5.5, the instantly claimed precipitated silicas demonstrate at least a 15% improvement in the disagglomeration rate. See comparative example 1 of para. [0186] and comparative example 2 of para. [0196]. However, precipitated silicas as claimed, particularly the association between the pH of less than 5.5 and the disagglomeration rate, in combination with the other properties as claimed, is neither taught nor suggested by the prior art.
Rather, while Valero allegedly refers to a precipitated silica having a pH of 4, and CTAB surface areas and an Ld falling within or overlapping with the claimed range, the reference is completely silent regarding the carbon content and the disagglomeration rate a of said silica. While Jacques is cited for teaching precipitated silicas having CTAB specific surface areas and carbon contents in the claimed ranges (see Examples 1 and 2 of Jacques), the pH of these silicas is 5.7 or 6.2 and thus lying outside the claimed range. Allain refers to precipitated silicas having CTAB specific surface areas and disagglomeration rates according to the claimed invention, but, also in this case, a pH value between 6.5 and 7.3 (see Examples 1 to 3 of Allain), which is also outside of the claimed range. Hence, both Jacques and Allain refer to precipitated silicas having pH values that are greater than the pH as required by the claimed invention.
The remarks are respectfully not persuasive. As mentioned in the rejection to Claim 13, Allain does disclose a disagglomeration rate of “at least 0.02 µm-1 min-1”. This is already greater than 0.5 x 10-2 µm-1 min-1, which would meet the claimed feature. Applicant then argues that the precipitated silica claimed is distinguishable from the reference because the reference does not describe the pH feature. However, as claimed, Valero teaches that after formation and prior to drying, the product has a pH at 4 (para. 235).
As to the carbon content and the disagglomeration rate, the disagglomeration rate was explained above. As to the carbon content, this feature is taught by Jacques. Applicant cites to the pH in Jacques as examples 1 and 2 are 5.7 and 6.2, higher than the range claimed. However, pH in Jacques can also be as low as 3.5 (see Claim 21 of Jacques). Further, the silica portion of Jacques is not relied on in the rejection, but only the use of carbon with precipitated silica, which Jacques explains reinforces the silicon.
Next, the remarks argue the following:
Furthermore, and as noted above, in contrast to the present application, none of the prior art documents refer to the relationship between the pH value and the disagglomeration rate. See paragraphs [0029]-[0030] of the present US specification. Additionally, none of these documents refer to the aim to improve the ability of the silica to disperse in elastomeric matrices. Id. para. [0010]. Put in other words, considering the cited prior art documents, a person of ordinary skill would have found no teaching or suggestion of a precipitated silica with all of the claimed characteristics. Rather, only a person already knowing the claimed invention would have had motivation to reduce the pH value of the silica to improve the dispersion ability.
Additionally, Applicant reminds the Examiner that a motivation to combine the prior art requires a reasonable expectation of success. For the present claims, said person would not have had such a reasonable expectation of success. On the contrary, one skilled in the art can expect a silica
having a high disagglomeration rate shows a good dispersion property. As can be seen from Examples 1 to 3 of Allain, the silica of Example 1, which has the highest pH value (7.3) shows the bestdisagglomeration rate (0.045 pm-1 min- Furthermore, according to Jacques, a precipitated silicahaving a carbon content of less than 1500 ppm but higher than zero has also a pH of above 5.5.
The remarks are respectfully disputed. The remarks ask for a relationship between pH and disagglomeration rate, but this is more narrow than the claims require. The claims only require a certain pH range and a certain disagglomeration rate and not a showing of a relationship between these values.
As to the dispersion, Nonetheless, Allain explains that the deagglomeration rate, α, is at least 0.02 µm-1 min-1.
The remarks then argue the following:
Hence, in view of these disclosures, a person skilled in the art would assume that, in order to provide a precipitated silica having a CTAB surface area and an Ld in the claimed range and additionally a disagglomeration rate a of equal or greater than 0.5x10-2m-1 min-1 and thus a good dispersion property as well as a carbon content of less than 1500 ppm, the pH value of the precipitated silica should be above 5.5, i.e., the pH value of the precipitated silica as described in Valero (i.e., pH 4) should be increased within the range of which Allain and Jacques teach to result in a carbon content and disagglomeration rate as claimed.
However, increasing the pH of the precipitated silica, specifically via the addition of a base, is not disclosed, taught or suggested in the prior art. Moreover, this is contrary to the teaching of the present claims where the pH of the precipitated silica must be below 5.5 to achieve the claimed disagglomeration rate. As such, the subject matter of current claims 1 and 15 would not have been obvious to a person skilled in the art.
The remarks are not persuasive. The assumptions above are conjecture and it is unclear that one of ordinary skill in the art would draw these conclusions.
As to the addition of a base, this is not claimed in the claims and therefore it is unclear the relevancy.
The remarks then argue the following:
In turning to the instantly claimed particle size distribution Ld, Applicant believes the Examiner's interpretation of the limitation is flawed. According to the Examiner, Maus allegedly discloses a precipitated silica having a particle size distribution that inherently satisfies the claimed Ld requirement "Ld of at least 1.2", since, when considering the d9s, dso, and ds values disclosed in
Maus in view of the Ld equation described in the present invention (Ld =(dg4 - di6)/dso), a value of 1.5 is obtained (see also the detailed discussion above).
However, the Examiner's assessment is largely based on the assumption that in the equation the numerator (ds4-di6) must be smaller than (d95-ds). While this is in principle may be correct, and this is actually so for any silica particle size distribution, the Examiner misses the following fundamental point: Maus' silica is characterized by a parameter Ld*, wherein Ld* is the width of the aggregate size distribution calculated with the following formula: Ld* = (d95-ds)/dso, which is greater than parameter Ld, (i.e., the width of the aggregate size distribution calculated with the formula of the present invention). However (and crucially) this is only true with the proviso that all the parameters dsdi6dso d84 and d95 are determined by the same method. Applicant believes that this is a crucial and key aspect that cannot be ignored in the present evaluation of the claimed feature Ld vis-a-vis the prior art.
Maus teaches ds, dso and d9s values (as determined by Maus' method) of less thanl0, less than 20 and less than 40 pm respectively, from which a Ld* value (Ld* = (d95 - ds)/dso )) of 1.5 can be calculated. The Ld (d =(dg4 - di6)/dso)) of Maus' silica (as determined by Maus' method) cannot be determined from Ld* (as determined by Maus' method) but it is necessarily <1.5 (and, necessarily outside the claimed value) as explained in more detail below.
Crucially, Maus' method to determine the particle size distribution and thus Ld or Ld* (according to the two different formulae provided above) is laser light scattering. On the other hand, the method used to determine the particle size distribution and thus Ld in accordance with the present claims is centrifugal sedimentation. It is well known to the skilled person in the art that laser light scattering, and centrifugal sedimentation are different methods that provide different results.
The Ld determined by laser light scattering is necessarily greater than the Ld determined by centrifugal sedimentation for the following reasons/differences. The differences arise from two main factors: the physical nature of silica aggregates (density effects) and the resolution capabilities of the measurement techniques, both of which are discussed below.
The remarks are not persuasive. First, the remarks that the range Ld*=(d95-d5)/d50 is greater than the parameter claimed is true. However, the value of Ld* is 1.5. The fact that Ld* is greater than Ld merely shows that the particle distribution range is much narrower than the Ld range. That is, the dispersion in the wide range set, D95-D5 is more uniform than the narrower range set of D84-D16 claimed. Further, the value of Ld required for the claims is 1.5, which is greater than 1.2 and therefore fulfills the “at least 1.2” value of Claim 1.
As to how the size is measured, the fact that the specification employs one method of measuring size, while the reference uses another should not disqualify the reference’s measurements since use of light scattering is a known and effective method of measuring particle size along with the centrifugal sedimentation process. Both methods are effective.
Applicant has argued extensively against the use of light scattering, the remarks are presented below.
Next, the remarks argue the following on pages 11-12:
1. Variable effective density (Fractal compression)
Precipitated silica consists of porous aggregates. The relationship between the size measured by laser diffraction (geometric volume and the size measured by centrifugation (hydrodynamic/Stokes behavior) is not linear.
- Laser diffraction measures the optical/geometric envelope of the aggregate. It sees the full size
of the "fluffy" aggregate.
- Centrifugal Sedimentation measures the Stokes diameters, which depends on both size and
density.
- The physics: large silica aggregates are fractal; as they grow larger, they become more porous
and their effective density decreases (approaching the density of the fluid). This means large aggregates settle disproportionately slower than solid spheres of the same size.
- The result: this phenomenon "compresses" the distribution curve in the centrifugal measurement. The large particles appear closer to the small particles in terms of settling time than they do in terms of geometric size. Consequently, the span (ds4-di6) measured by centrifugation is physically compressed leading to a lower Ld.
2. Instrument Resolution and Broadening
- Laser diffraction (low resolution): this technique relies on fitting light scattering patterns to a model. It inherently suffers from "instrumental broadening" or smearing. It tends to report a broader distribution (Larger Ld) even for narrow samples because it struggles to resolve sharp
differences in particle populations.
- Centrifugal sedimentation (high resolution): this technique separates particles physically by mass and drag. It has very high resolution and can distinguish distinct populations without smearing them together. This lack of artificial broadening results in a steeper curve and a lower Ld.
In sum, when a precipitated silica has a parameter Ld determined by laser light scattering of 1.5, the most likely Ld value as determined by centrifugal sedimentation will be substantially lower. Thus, if Maus had determined Ld* parameters by centrifugal sedimentation (as required by the present invention), they would have obtained a much lower Ld value, in the range of 0.8 to 1.2 (typically about 1.0), instead of obtaining 1.5 by laser light scattering. Since Maus' Ld silica determined by a given method is necessarily significantly lower that Maus' Ld* silica as determined by the same method, Maus' Ld silica determined by centrifugal sedimentation is necessarily lower than Maus' Ld silica determined by centrifugal sedimentation, that is to say Maus' Ld silica determined by centrifugal sedimentation is necessarily significantly lower than 1.2, probably even lower than 1.0, which does not correspond with the present claims.
The remarks are respectfully not persuasive. The attached article by Ferro et al. “Comparing particle size distribution analysis by sedimentation and laser diffraction method” states in their conclusion that the methods using centrifuge sedimentation (particularly use of the Sieve-Hydrometer method, which is a type of centrifuge sedimentation) and laser diffraction are essentially equal (see Conclusion, section 5 on page 40).
The reference explained that some interpretative variation with laser diffraction has been discussed and that these differences may account for the size discrepancies (see section 2, para. 4-5, 6). For instance, when the particles absorb some light, use of the Mie theory instead of the Maxwell equations provide a solution for some light transmission through the particle by taking into account eh refractive index of the material (see section 2, last para on page 36). Use of certain other theories have been used (see section 2, para. 6-8 on page 37), but the Mie theory was preferred (section 2, para. 5 and conclusion, section c).
Moreover, in Bitelli “Experimental evidence of laser diffraction accuracy for particle size analysis”, the reference states that when comparing laser scattering to sedimentation, the results found that there was a “large over-estimation of small size classes by sedimentation methods with respect to laser” diffraction (see conclusion, section 4, para. 3, lines 5-7). Therefore, in studies done comparing these two analysis methods, laser diffraction was preferred and determined to be more accurate over sedimentation methods.
Finally, the remarks argue the following:
Last, but not least, Applicant respectfully points out that Maus' silica, as acknowledged by the Examiner themself, is produced by a device which is designed to prepare a silica with a significantly narrower distribution: "Maus describes a precipitated silica having a narrow particle size distribution (title). The reference explains that having finer and narrower particle size is desirable (col. 1, lines 33-35). One method Maus achieves this is by [...]. This device produces a silica [...] with a significantly lower distribution (col. 4, lines 12-15). After production, the particles can be further narrowed in size and distribution by using classifiers ".
Opposite from the teachings of Maus, the instantly claimed precipitated silica is characterized by a significantly broader distribution. Consistently, it can be advantageously prepared by a process which is designed to allow for the obtention of this broader distribution, namely a particular process which comprises a step of simultaneously adding a silicate and an acid to a reaction medium such that the pH of the reaction medium is maintained in the range of from 2.0 to 5.0, and thereafter a step of simultaneously adding a silicate and an acid to a reaction medium such that that the pH of the reaction medium is maintained in the range from 7.0 to 10.0.
These remarks are respectfully not persuasive. The particle size distribution claimed is a narrower size distribution as evidenced by the claimed formula: Ld = (d84-d16)/d50 > 1.2 and the cited Maus reflected that this was known in the art.
Claim Rejections - 35 USC § 112
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 26 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 26 describes the claimed precipitated silica is terms of V(d5-d50)/V(d5-d100). According to the specification, this is limited to the pore distribution of the silica and not the silica itself. Since the specification only provides support for this narrower interpretation, this claim will be examined in terms of the pore volume. Correction is required.
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.
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.
Claim(s) 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 21, 22, 23, 24, 27 is/are rejected under 35 U.S.C. 103 as being unpatentable over Valero (US Pub.: 2005/0032965) and in view of Jacques (EP 0280623) and in view of Maus (US Pat.: 6902715).
As to Claims 1, 2, 3, 4, 5, 6, 14, 21, 22, 23 and 24, Valero describes a precipitative-silica type silica (para. 52, 54, 203, 305, 398, 418). The silica has a CTAB surface area (SCTAB) ranging from 40 to 525 m2/g (abstract). The size distribution width Ld of at least about 1.04 (para. 0129). Although Valero does not specifically teach that the Ld is at least 1.2. However, “at least about 1.04” overlaps the range of “at least 1.2”. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05.
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05.
Nonetheless, this feature is taught by the Maus reference below.
As to the pH, Valero teaches that after formation and prior to drying, the product has a pH at 4 (para. 235).
Since Valero does not specifically teach what the carbon content is, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the carbon content would be as close to zero as possible. Nonetheless, a low carbon content is precipitated silica is known in the art.
As to the carbon content, Jacques teaches a method of precipitating silica (title). Their method is used to improve the qualities of precipitating silica reinforcing agent for silicon applications and also useable for reinforcement of elastomers (page 2, lines 11-17). In their precipitate silica, Jacques shows that the carbon content can be higher, such as 370ppm (see example 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the carbon content to be in a range of about 370ppm, as taught by Jacques for use with Valero because this amount is known to be effective in reinforcement of elastomers.
As to the width of the aggregate size distribution Ld, the specification of this application defines this feature as: Ld = (d84-d16)/d50 (see published specification, para. 22). Maus describes a precipitated silica having a narrow particle size distribution (title). The reference explains that having finer and narrower particle size distribution is desirable (col. 1, lines 33-35). One method Maus achieves this is by use of a pulse combustion dryer (col. 2, lines 40-42) with a conventional silica precipitating process (col. 4, lines 33-39). This device produces a silica with a comparatively smaller size (col. 2, lines 59-60) with a significantly narrower distribution (col. 4, lines 12-15). After production, the particles can be further narrowed in size and distribution by using classifiers (col. 7, lines 8-10, 47-52). The silica particles obtained in their invention has the following size distribution: d95=40, d50<20 and d5<10µm (col. 1, lines 45-50).
When plugged into the equation of the specification defining the Ld values of the claim, the Ld value is: 1.5. Although these values are wider than the equation for Ld, d95 being father than d84 and d5 being further down than d16, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the d95 and d5 values capture a wider particle size range and would include values in the d84 and d16 range. Furthermore, a smaller Ld value using the wider values of d95 and d5 would have an even smaller Ld range when using the d84 and d16 values.
As to Claims 5 and 6, Maus teaches an Ld value of 1.5 (see above).
As to Claims 7, 8, 9, 10 and 11, Valero teaches a pH of 2.5 to 5 (para. 21) or from 3 to 4.5 (para. 22). Therefore, in some embodiments, the pH of the solution is from 4.5 to 3.5. A prima facie case of obviousness exists where the claimed ranges and prior art ranges overlap or are close enough that one skilled in the art would have expected them to have the same properties. See MPEP 2144.05 I.”
As to Claim 12, Valero teaches making their precipitated silica using sodium silicate and sulfuric acid (para. 210). The mixture does not contain a carbon-containing compound. After this step, Valero teaches adding a polymer (para. 213), which is a carbon-containing compound. However, the current application similarly combines silica with an acid (see published specification, para. 72-78). This application also teaches that a natural or synthetic polymer can be added to the mixture (see published specification, para. 106). Therefore, given that the contents of the mixture do not contain carbon prior to adding the polymer, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention the composition would have close to zero carbon.
As to Claim 14, Valero teaches that the value of V(d5-d50)/V(d5-d100)= 0.74 (para. 218).
As to Claim 13, this claim describes a hypothetical situation. Nonetheless, Allain explains that the deagglomeration rate, α, is at least 0.02 µm-1 min-1 (para. 270). The reference does not state that if the pH was higher, the deagglomeration rate would be at least 15% lower. However, in this hypothetical situation, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that a higher pH would have a deagglomeration rate that is at least 15% lower than one with a lower pH.
As to Claim 15, Valero describes a precipitative-silica type silica (para. 52, 54, 203, 305, 398, 418). The silica has a CTAB surface area (SCTAB) ranging from 40 to 525 m2/g (abstract). The size distribution width Ld of at least about 1.04 (para. 0129). Although Valero does not specifically teach that the Ld is at least 1.2. However, “at least about 1.04” overlaps the range of “at least 1.2”. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05.
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05.
Nonetheless, this feature is taught by the Maus reference below.
As to the pH, Valero teaches that after formation and prior to drying, the product has a pH at 4 (para. 235).
Since Valero does not specifically teach what the carbon content is, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the carbon content would be as close to zero as possible. Nonetheless, a low carbon content is precipitated silica is known in the art.
As to the carbon content, Jacques teaches a method of precipitating silica (title). Their method is used to improve the qualities of precipitating silica reinforcing agent for silicon applications and also useable for reinforcement of elastomers (page 2, lines 11-17). In their precipitate silica, Jacques shows that the carbon content can be higher, such as 370ppm (see example 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the carbon content to be in a range of about 370ppm, as taught by Jacques for use with Valero because this amount is known to be effective in reinforcement of elastomers.
As to the width of the aggregate size distribution Ld, the specification of this application defines this feature as: Ld = (d84-d16)/d50 (see published specification, para. 22). Maus describes a precipitated silica having a narrow particle size distribution (title). The reference explains that having finer and narrower particle size distribution is desirable (col. 1, lines 33-35). One method Maus achieves this is by use of a pulse combustion dryer (col. 2, lines 40-42) with a conventional silica precipitating process (col. 4, lines 33-39). This device produces a silica with a comparatively smaller size (col. 2, lines 59-60) with a significantly narrower distribution (col. 4, lines 12-15). After production, the particles can be further narrowed in size and distribution by using classifiers (col. 7, lines 8-10, 47-52). The silica particles obtained in their invention has the following size distribution: d95=40, d50<20 and d5<10µm (col. 1, lines 45-50).
When plugged into the equation of the specification defining the Ld values of the claim, the Ld value is: 1.5. Although these values are wider than the equation for Ld, d95 being father than d84 and d5 being further down than d16, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the d95 and d5 values capture a wider particle size range and would include values in the d84 and d16 range. Furthermore, a smaller Ld value using the wider values of d95 and d5 would have an even smaller Ld range when using the d84 and d16 values.
As to the carbon content, Valero teaches making their precipitated silica using sodium silicate and sulfuric acid (para. 210). The mixture does not contain a carbon-containing compound. After this step, Valero teaches adding a polymer (para. 213), which is a carbon-containing compound. However, the current application similarly combines silica with an acid (see published specification, para. 72-78). This application also teaches that a natural or synthetic polymer can be added to the mixture (see published specification, para. 106). Therefore, given that the contents of the mixture do not contain carbon prior to adding the polymer, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention the composition would have close to zero carbon.
As to Claim 16, Valero teaches that the silica can be dispersed in a polymer (para. 0157, 0187). Also, Valero teaches that the polymer used can be an elastomer (para. 189, 190, 192, 2).
As to Claim 27, Valero teaches that the polymer used is an elastomer (para. 190).
Claim(s) 18, 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Valero, Jacques and Maus as applied to claims 1 or 5 above, and further in view of Bernard (US Pat.: 5723529).
Valero teaches that the silica described is known to be used with elastomers (para. 2, 189), but not that it is used with tire treads.
Bernard describes a silica composition used to reinforce elastomers for tire treads (title).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the silica of Valero, Jacques and Maus with elastomers in tire treads, as taught by Bernard because these are known to reinforce elastomers in tire treads.
Claim(s) 7, 8, 9, 10, 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Valero (US Pub.: 2005/0032965) and in view of Jacques (EP 0280623) and in view of Allain (WO 2009/112458).
Valero describes a precipitated-silica type silica (para. 52, 54, 203, 305, 398, 418). The silica has a CTAB surface area (SCTAB) ranging from 40 to 525 m2/g (abstract). The size distribution width Ld of at least about 1.04 (para. 0129). Although Valero does not specifically teach that the Ld is at least 1.2. However, “at least about 1.04” overlaps the range of “at least 1.2”. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05.
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05.
As to the pH, Valero teaches that after formation and prior to drying, the product has a pH at 4 (para. 235).
As to the deagglomeration feature, Allain teaches a process for precipitating silica (para. 1). The process of preparing the silica involves first acidifying silicate (para. 8), followed by increasing the pH of the solution using an alkaline agent (para. 9). The product formed has a CTAB of 60-400 m2/g (para. 253).
The product formed undergoes a deagglomeration test (para. 0168). As to the deagglomeration speed, denoted α, this is measured using certain device useable to measure the evolution of the average size of the particle agglomerates (page 36, para. 246). The deagglomeration rate is at least 0.02 µm-1 min-1 (para. 270). The characteristics of this precipitated silica have improved hysteresis and reinforcement properties (para. 6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain a precipitated silica with a deagglomerate rate of 0.02 µm-1 min-1, as taught by Allain for use with the precipitated silica of Valero and Jacques because this property is known to improve hysteresis and reinforcement properties of the precipitated silica.
Claim(s) 19 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Valero, Jacques and Maus as applied to claim 18 above, and further in view of Guy (US Pub.: 2015/0284546).
The references teach use of precipitated silica in elastomers (see above), but not for use in tires or tire treads.
Guy describes uses for precipitated silica (title). The reference explains that they are compositions in elastomers (abstract), which includes tires and in particular tire treads (para. 208 and 210).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the precipitated silica for use in elastomers and then used in tires and tire treads, as taught by Guy for use with Valero, Jacques and Maus because it is known to effectively make tires and tire components using precipitated silica in elastomers.
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Valero, Jacques and Maus as applied to claim 5 above, and further in view of Boivin (FR 3017609), EPO translation.
Valero, Jacques and Maus do not teach the volume of pores in the precipitated silica.
Boivin describes precipitated silica (para. 1) effective for a large variety of uses as filler material (see Field of Invention, para. 1). The pH of the solution is from 2-5 (para. 13), the CTAB surface area is from 40-525 m2/g (para. 30, 3rd para). The carbon content can be 0.15wt% (para. 30, 3rd para.).
As to the volume feature, Boivin teaches that the V(d5-d50)/V(d5-d100) of at least 0.73 to 0.84 (para. 30, last para).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a volume of V(d5-d50)/V(d5-d100) of at least 0.73 to 0.84 in the precipitated silica, as taught by Boivin for use with the precipitated silica of Valero, Jacques and Maus because this pore volume range is known to be useful in silica used as filler material.
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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHENG HAN DAVIS whose telephone number is (571)270-5823. The examiner can normally be reached 9-5:30. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Fung Coris can be reached at 571-270-5713. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/SHENG H DAVIS/Primary Examiner, Art Unit 1732 March 13, 2026