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 .
Election/Restrictions
Applicant's election with traverse of Group I, claims 1-13, in the reply filed on 01/10/2026 is acknowledged. The traversal is on the ground(s) that the claims are entitled to be examined in a single application, as the claims are so linked together as to form a single general inventive concept. This is not found persuasive because this application contains the following inventions or groups of inventions which are not so linked as to form a single general inventive concept under PCT Rule 13.1.
Group I, claim(s) 1-13, drawn to a continuous method for the preparation of a silicone rubber base composition.
Group II, claim(s) 14 and 17-20, drawn to a silicone rubber based composition assembly adapted to make a silicone rubber based composition by the continuous method accordance with claim 1.
The groups of inventions listed above do not relate to a single general inventive concept under PCT Rule 13.1 because, under PCT Rule 13.2, they lack the same or corresponding special technical features for the following reasons:
Groups I and II lack unity of invention because even though the inventions of these groups require the technical feature of a silicone rubber base composition manufacturing assembly comprising a first static mixer (25), a first twin-screw extruder (4), a reinforcing silica filler (B) entry port (27), at least one vent (5) to the atmosphere upstream of the reinforcing silica filler (B) entry port (27), and a residence zone (17) downstream of the first twin-screw extruder (4), this technical feature is not a special technical feature as it does not make a contribution over the prior art in view of Schoeley et al. (EP 0849330 A2, cited in IDS, machine translation in English used for citation, made of record on 12/15/2023) in view of Mount (Mount, 2017, Applied Plastics Engineering Handbook - Processing, Materials, and Applications, 2nd Edition, - 12 Extrusion Processes, Elsevier, Retrieved from https://app.knovel.com/hotlink/pdf/id:kt011DYC4T/applied-plastics-engineering/twin-screw-extruder-equipment). Schoeley teaches incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], wherein the devolatilizing removes the hexamethyldisiloxane and the volatile compounds and is in vacuo [0028], which is by vacuum [0013], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035], wherein the hexamethyldisiloxane [0034] is a hexalkyldisiloxane that is used as a volatile, low molecular weight organosilicon compound containing no hydrolysable groups and which are non-reactive with respect to the surface of the silica [0014], wherein the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], wherein the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], wherein when using silazanes, it is customary to work in the presence of water [0024], wherein it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], wherein incorporation of the silica into the mixture can be carried out batchwise in a two-screw kneader [0018], wherein the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], wherein optionally the hexamethyldisilazane is present in the mixture before the silica is incorporated into the mixture [0028] instead of after the silica is incorporated into the mixture [0034], which suggests placing Schoeley’s hexamethyldisilazane and Schoeley’s water in Schoeley’s mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane in a two-shaft kneader, then carrying out Schoeley’s steps of incorporating silica into the mixture, kneading the mixture, and doing a second kneading in a continuously operating mixing unit that is a twin-screw extruder, and which suggests carrying out a second of Schoeley’s hydrophobic treatment with hexamethyldisilazane during or after Schoeley’s step of doing a second kneading. Schoeley’s teachings therefore read on a method, that is optionally a continuous method, for the preparation of a silicone rubber base composition, the composition comprising (A) one or more polyorganosiloxanes containing at least two unsaturated groups per molecule selected from alkenyl groups, and (B’) a hydrophobically treated reinforcing silica filler, said method comprising the steps of (a) introducing (C) at least one hydrophobing treating agent and component (A), and (D) water, into a first static mixer (25) to form a step (a) mixture and optionally then introducing the step (a) mixture on to a first twin-screw extruder (4), (b) introducing (B) reinforcing silica filler optionally into the step (a) mixture via a reinforcing silica filler (B) entry port (27) in the first twin-screw extruder (5) while maintaining the temperature in a range of between 20 to 25 °C to form a viscous paste, c) mixing the viscous paste resulting from step (b) in a dispersive mixing and kneading zone optionally in the first twin-screw extruder (4) to form a silica dispersion, optionally (d) further mixing the silica dispersion produced in step (c) in a residence zone (17) downstream of the first twin-screw extruder (4) to provide an unstripped silicone rubber base composition, (e) stripping the unstripped silicone rubber base composition with vacuum stripping to provide a silicone rubber based composition at a temperature of at greater than 100 °C, and optionally (f) introducing component (C) intro the first twin-screw extruder (4) between steps (c) and (d) and/or during step (d) to dilute and further hydrophobically treat silica from the silica dispersion of step (c) and subsequently form a diluted silica dispersion, wherein (i) component (A) comprises one or more polydiorganosiloxanes containing at least two alkenyl groups per molecule and optionally a polyorganosiloxane resin containing at least two alkenyl groups per molecule, and/or (ii) additives are introduced into the mixture during the preparation, wherein the further mixing in step (e) is carried out in a residence zone (17).
Schoeley does not teach a specific embodiment in which the method is a continuous method, that the step (a) further comprises then introducing the step (a) mixture on to a first twin-screw extruder (4), that the step of (b) introducing (B) reinforcing silica filler is into the step (a) mixture via a reinforcing silica filler (B) entry port (27) in the first twin-screw extruder (4) while maintaining the temperature in a range of between 20 to 80 °C to form a viscous paste and providing at least one vent to the atmosphere upstream of the reinforcing silica filler (B) entry port (27) to allow gases present to escape, that the step (c) mixing the viscous paste resulting from step (b) is in a dispersive mixing and kneading zone in the first twin-screw extruder (4) to form a silica dispersion, and that the step (d) further mixing the silica dispersion produced in step (c) is in a residence zone (17) downstream of the first twin-screw extruder (4) to provide an unstripped silicone rubber based composition, wherein the further mixing in step (e) is carried out in a residence zone (17) optionally comprising a third static mixer. However, Mount teaches that additional barrel sections are normally added to increase process flexibility for down stream venting (p. 238), that screws are modular with different elements combined in a strategic design to localize venting at specific locations along the extruder barrel (p. 238), that venting is the ability of the extruder to remove volatiles through a single or multiple vent ports along the barrel length (p. 240), that a vent barrel has an opening on top that may be either circular or rectangular and is used to vent volatiles from the barrel or to feed different components of the formulation (p. 244), that barrel sections containing a vent plug can be used to vent volatiles with the use of a vent stack (p. 244), that the vent stack can open for atmospheric venting (p. 244), and that screw elements are modular and are inserted on to the screw shafts to provide the proper venting to produce a commercially acceptable product (p. 244). Schoeley and Mount are analogous art because both references are in the same field of endeavor of a continuous method that uses a twin-screw extruder, or Schoeley and Mount are reasonably pertinent to the problem of selecting types of twin-screw extruders for a continuous method. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to place Schoeley’s hexamethyldisilazane and Schoeley’s water in Schoeley’s mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane in Schoeley’s two-shaft kneader, then feeding the resulting mixture into Scholey’s continuously operating mixing unit that is a twin-screw extruder, then carry out Schoeley’s steps of incorporating silica into the mixture, kneading the mixture at 130° C for 1 hour, and doing a second kneading at 130° C for 1 h in Schoeley’s continuously operating mixing unit that is a twin-screw extruder, wherein the twin-screw extruder has a vent port for atmospheric venting to vent volatiles and that is located upstream of where Schoeely’s silica is incorporated into the mixture, remove the resulting mixture from the twin-screw extruder, and further mix the resulting mixture in another of Schoeley’s two-shaft kneader before Schoeley’s step of devolatilizing. The proposed modification would read on the method is a continuous method, that the step (a) further comprises then introducing the step (a) mixture on to a first twin-screw extruder (4), that the step of (b) introducing (B) reinforcing silica filler is into the step (a) mixture via a reinforcing silica filler (B) entry port (27) in the first twin-screw extruder (4) while maintaining the temperature in a range of between 20 to 25 °C to form a viscous paste and providing at least one vent to the atmosphere upstream of the reinforcing silica filler (B) entry port (27) to allow gases present to escape, that the step (c) mixing the viscous paste resulting from step (b) is in a dispersive mixing and kneading zone in the first twin-screw extruder (4) to form a silica dispersion, and that the step (d) further mixing the silica dispersion produced in step (c) is in a residence zone (17) downstream of the first twin-screw extruder (4) to provide an unstripped silicone rubber based composition as claimed, wherein the further mixing in step (e) is carried out in a residence zone (17) as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that incorporation of the silica into the mixture can be carried out batchwise in a two-screw kneader [0018], that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], which means that the proposed modification would have been beneficial for modifying a rate of production of product of Schoeley’s method, that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], that optionally the hexamethyldisilazane is present in the mixture before the silica is incorporated into the mixture [0028] instead of after the silica is incorporated into the mixture [0034], which means that the proposed modification would have been beneficial for modifying the effectiveness of Schoeley’s hydrophobic treatment of the surface of the silica, and that the proposed modification would have bene beneficial for allowing one of ordinary skill in the art to transfer Schoeley’s mixture from Schoeley’s two-shaft kneader to Schoeley’s twin-screw extruder. Also, one of ordinary skill in the art would have been motivated to do so because Mount teaches that venting is the ability of the extruder to remove volatiles through a single or multiple vent ports along the barrel length (p. 240), that that barrel sections containing a vent plug can be used to vent volatiles with the use of a vent stack (p. 244), that the vent stack can open for atmospheric venting (p. 244), and that screw elements are modular and are inserted on to the screw shafts to provide the proper venting to produce a commercially acceptable product (p. 244), which means that the proposed modification would have been beneficial for providing proper venting to produce a commercially acceptable product of Schoeley’s method.
Schoeley does not teach a specific embodiment in which said method further comprises the step of (f) introducing component (C) and optionally one or both of components (A) and (D) either into the first twin-screw extruder (4) between steps (c) and (d) and/or during step (d) to dilute and further hydrophobically treat silica from the silica dispersion of step (c) and subsequently form a diluted silica dispersion. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to carry out a second of Schoeley’s hydrophobic treatment with hexamethyldisilazane and water by feeding Schoeley’s hexamethyldisilazane and water to the mixture resulting from Schoeley’s second kneading in Schoeley’s twin-screw extruder. The proposed modification would read on which said method further comprises the step of (f) introducing component (C) either into the first twin-screw extruder (4) between steps (c) and (d) to dilute and further hydrophobically treat silica from the silica dispersion of step (c) and subsequently form a diluted silica dispersion as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], and that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], which means that the proposed modification would have been beneficial for modifying the effectiveness of Schoeley’s hydrophobic treatment of the surface of the silica.
The traversal is also on the ground(s) that claims 1 and 14 share at least one special technical feature because claim 1 requires providing at least one vent to the atmosphere upstream of the reinforcing silica filler entry port to allow gases present to escape, and claim 14 requires at least one vent (5) to the atmosphere upstream of the reinforcing silica filler (B) entry port (27). This is not found persuasive because Groups I and II lack unity of invention because even though the inventions of these groups require the technical feature of a silicone rubber base composition manufacturing assembly comprising a first static mixer (25), a first twin-screw extruder (4), a reinforcing silica filler (B) entry port (27), at least one vent (5) to the atmosphere upstream of the reinforcing silica filler (B) entry port (27), and a residence zone (17) downstream of the first twin-screw extruder (4), this technical feature is not a special technical feature as it does not make a contribution over the prior art in view of Schoeley in view of Mount as explained above.
The traversal is also on the ground(s) that it is believed that Schoeley does not disclose, teach, or suggest the special technical feature of providing at least one vent to the atmosphere upstream of the reinforcing silica filler entry port to allow gases present to escape and at least one vent (5) to the atmosphere upstream of the reinforcing silica filler (B) entry port (27). This is not found persuasive because Groups I and II lack unity of invention because even though the inventions of these groups require the technical feature of a silicone rubber base composition manufacturing assembly comprising a first static mixer (25), a first twin-screw extruder (4), a reinforcing silica filler (B) entry port (27), at least one vent (5) to the atmosphere upstream of the reinforcing silica filler (B) entry port (27), and a residence zone (17) downstream of the first twin-screw extruder (4), this technical feature is not a special technical feature as it does not make a contribution over the prior art in view of Schoeley in view of Mount as explained above.
The requirement is still deemed proper and is therefore made FINAL.
Claims 14 and 17-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 01/10/2026.
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
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.
Claims 1-13 are 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 1 recites the limitation “a range of between 20 to 80” in line 12, which is indefinite because the upper and lower limits of the range are unclear because the term “between” means greater than a first number and less than a second number, and the term “to” means from some a first number to a second number. It is unclear if the range is greater than 20 and less than 80, or if the range is from 20 to 80. Based on the specification of the instant application [0014, 0054, 0059], for further examination of the claims, this imitation is interpreted as “a range of between 20 and 80”.
Claim 10 recites the limitation “the further mixing in step (e)” in line 2. There is insufficient antecedent basis for this limitation in the claim because claim 1 does not recite “further mixing” in step “(e)”. Since claim 1 recites “(d) further mixing the silica dispersion produced in step (c) in a residence zone (17)” in line 17, for further examination of the claims, this limitation is interpreted as “the further mixing in step (d)”.
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.
Claims 1, 2, 4-6, and 8-13 are rejected under 35 U.S.C. 103 as being unpatentable over Schoeley et al. (EP 0849330 A2, cited in IDS, machine translation in English used for citation, made of record on 12/15/2023) in view of Mount (Mount, 2017, Applied Plastics Engineering Handbook - Processing, Materials, and Applications, 2nd Edition, - 12 Extrusion Processes, Elsevier, Retrieved from https://app.knovel.com/hotlink/pdf/id:kt011DYC4T/applied-plastics-engineering/twin-screw-extruder-equipment).
Regarding claims 1, 4, and 10, Schoeley teaches incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], wherein the devolatilizing removes the hexamethyldisiloxane and the volatile compounds and is in vacuo [0028], which is by vacuum [0013], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035], wherein the hexamethyldisiloxane [0034] is a hexalkyldisiloxane that is used as a volatile, low molecular weight organosilicon compound containing no hydrolysable groups and which are non-reactive with respect to the surface of the silica [0014], wherein the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], wherein the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], wherein when using silazanes, it is customary to work in the presence of water [0024], wherein it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], wherein incorporation of the silica into the mixture can be carried out batchwise in a two-screw kneader [0018], wherein the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], wherein optionally the hexamethyldisilazane is present in the mixture before the silica is incorporated into the mixture [0028] instead of after the silica is incorporated into the mixture [0034], which suggests placing Schoeley’s hexamethyldisilazane and Schoeley’s water in Schoeley’s mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane in a two-shaft kneader, then carrying out Schoeley’s steps of incorporating silica into the mixture, kneading the mixture, and doing a second kneading in a continuously operating mixing unit that is a twin-screw extruder, and which suggests carrying out a second of Schoeley’s hydrophobic treatment with hexamethyldisilazane during or after Schoeley’s step of doing a second kneading. Schoeley’s teachings therefore read on a method, that is optionally a continuous method, for the preparation of a silicone rubber base composition, the composition comprising (A) one or more polyorganosiloxanes containing at least two unsaturated groups per molecule selected from alkenyl groups, and (B’) a hydrophobically treated reinforcing silica filler, said method comprising the steps of (a) introducing (C) at least one hydrophobing treating agent and component (A), and (D) water, into a first static mixer (25) to form a step (a) mixture and optionally then introducing the step (a) mixture on to a first twin-screw extruder (4), (b) introducing (B) reinforcing silica filler optionally into the step (a) mixture via a reinforcing silica filler (B) entry port (27) in the first twin-screw extruder (5) while maintaining the temperature in a range of between 20 to 25 °C to form a viscous paste, c) mixing the viscous paste resulting from step (b) in a dispersive mixing and kneading zone optionally in the first twin-screw extruder (4) to form a silica dispersion, optionally (d) further mixing the silica dispersion produced in step (c) in a residence zone (17) downstream of the first twin-screw extruder (4) to provide an unstripped silicone rubber base composition, (e) stripping the unstripped silicone rubber base composition with vacuum stripping to provide a silicone rubber based composition at a temperature of at greater than 100 °C, and optionally (f) introducing component (C) intro the first twin-screw extruder (4) between steps (c) and (d) and/or during step (d) to dilute and further hydrophobically treat silica from the silica dispersion of step (c) and subsequently form a diluted silica dispersion, wherein (i) component (A) comprises one or more polydiorganosiloxanes containing at least two alkenyl groups per molecule and optionally a polyorganosiloxane resin containing at least two alkenyl groups per molecule, and/or (ii) additives are introduced into the mixture during the preparation, wherein the further mixing in step (e) is carried out in a residence zone (17).
Schoeley does not teach a specific embodiment in which the method is a continuous method, that the step (a) further comprises then introducing the step (a) mixture on to a first twin-screw extruder (4), that the step of (b) introducing (B) reinforcing silica filler is into the step (a) mixture via a reinforcing silica filler (B) entry port (27) in the first twin-screw extruder (4) while maintaining the temperature in a range of between 20 to 80 °C to form a viscous paste and providing at least one vent to the atmosphere upstream of the reinforcing silica filler (B) entry port (27) to allow gases present to escape, that the step (c) mixing the viscous paste resulting from step (b) is in a dispersive mixing and kneading zone in the first twin-screw extruder (4) to form a silica dispersion, and that the step (d) further mixing the silica dispersion produced in step (c) is in a residence zone (17) downstream of the first twin-screw extruder (4) to provide an unstripped silicone rubber based composition, wherein the further mixing in step (e) is carried out in a residence zone (17) optionally comprising a third static mixer. However, Mount teaches that additional barrel sections are normally added to increase process flexibility for down stream venting (p. 238), that screws are modular with different elements combined in a strategic design to localize venting at specific locations along the extruder barrel (p. 238), that venting is the ability of the extruder to remove volatiles through a single or multiple vent ports along the barrel length (p. 240), that a vent barrel has an opening on top that may be either circular or rectangular and is used to vent volatiles from the barrel or to feed different components of the formulation (p. 244), that barrel sections containing a vent plug can be used to vent volatiles with the use of a vent stack (p. 244), that the vent stack can open for atmospheric venting (p. 244), and that screw elements are modular and are inserted on to the screw shafts to provide the proper venting to produce a commercially acceptable product (p. 244). Schoeley and Mount are analogous art because both references are in the same field of endeavor of a continuous method that uses a twin-screw extruder, or Schoeley and Mount are reasonably pertinent to the problem of selecting types of twin-screw extruders for a continuous method. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to place Schoeley’s hexamethyldisilazane and Schoeley’s water in Schoeley’s mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane in Schoeley’s two-shaft kneader, then feeding the resulting mixture into Scholey’s continuously operating mixing unit that is a twin-screw extruder, then carry out Schoeley’s steps of incorporating silica into the mixture, kneading the mixture at 130° C for 1 hour, and doing a second kneading at 130° C for 1 h in Schoeley’s continuously operating mixing unit that is a twin-screw extruder, wherein the twin-screw extruder has a vent port for atmospheric venting to vent volatiles and that is located upstream of where Schoeely’s silica is incorporated into the mixture, remove the resulting mixture from the twin-screw extruder, and further mix the resulting mixture in another of Schoeley’s two-shaft kneader before Schoeley’s step of devolatilizing. The proposed modification would read on the method is a continuous method, that the step (a) further comprises then introducing the step (a) mixture on to a first twin-screw extruder (4), that the step of (b) introducing (B) reinforcing silica filler is into the step (a) mixture via a reinforcing silica filler (B) entry port (27) in the first twin-screw extruder (4) while maintaining the temperature in a range of between 20 to 25 °C to form a viscous paste and providing at least one vent to the atmosphere upstream of the reinforcing silica filler (B) entry port (27) to allow gases present to escape, that the step (c) mixing the viscous paste resulting from step (b) is in a dispersive mixing and kneading zone in the first twin-screw extruder (4) to form a silica dispersion, and that the step (d) further mixing the silica dispersion produced in step (c) is in a residence zone (17) downstream of the first twin-screw extruder (4) to provide an unstripped silicone rubber based composition as claimed, wherein the further mixing in step (e) is carried out in a residence zone (17) as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that incorporation of the silica into the mixture can be carried out batchwise in a two-screw kneader [0018], that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], which means that the proposed modification would have been beneficial for modifying a rate of production of product of Schoeley’s method, that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], that optionally the hexamethyldisilazane is present in the mixture before the silica is incorporated into the mixture [0028] instead of after the silica is incorporated into the mixture [0034], which means that the proposed modification would have been beneficial for modifying the effectiveness of Schoeley’s hydrophobic treatment of the surface of the silica, and that the proposed modification would have bene beneficial for allowing one of ordinary skill in the art to transfer Schoeley’s mixture from Schoeley’s two-shaft kneader to Schoeley’s twin-screw extruder. Also, one of ordinary skill in the art would have been motivated to do so because Mount teaches that venting is the ability of the extruder to remove volatiles through a single or multiple vent ports along the barrel length (p. 240), that that barrel sections containing a vent plug can be used to vent volatiles with the use of a vent stack (p. 244), that the vent stack can open for atmospheric venting (p. 244), and that screw elements are modular and are inserted on to the screw shafts to provide the proper venting to produce a commercially acceptable product (p. 244), which means that the proposed modification would have been beneficial for providing proper venting to produce a commercially acceptable product of Schoeley’s method.
Schoeley does not teach a specific embodiment in which said method further comprises the step of (f) introducing component (C) and optionally one or both of components (A) and (D) either into the first twin-screw extruder (4) between steps (c) and (d) and/or during step (d) to dilute and further hydrophobically treat silica from the silica dispersion of step (c) and subsequently form a diluted silica dispersion. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to carry out a second of Schoeley’s hydrophobic treatment with hexamethyldisilazane and water by feeding Schoeley’s hexamethyldisilazane and water to the mixture resulting from Schoeley’s second kneading in Schoeley’s twin-screw extruder. The proposed modification would read on which said method further comprises the step of (f) introducing component (C) either into the first twin-screw extruder (4) between steps (c) and (d) to dilute and further hydrophobically treat silica from the silica dispersion of step (c) and subsequently form a diluted silica dispersion as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], and that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], which means that the proposed modification would have been beneficial for modifying the effectiveness of Schoeley’s hydrophobic treatment of the surface of the silica.
Regarding claim 2, Schoeley teaches that the amount of the hexamethyldisilazane added is 24 g, that the amount of the dimethylvinylsiloxyl-terminated polydimethylsiloxane added is 65 g, that the amount of the water added is 6 g [0034], and since Schoeley does not teach the amount of time taken to add the hexamethyldisilazane, the dimethyvinylsiloxyl-terminated polydimethylsiloxane, and the water, the total amounts of them were added at the same time, which reads on wherein components (C) and (A), and component (D) when present, are introduced into the first static mixer (25) at pre-defined controlled rates, which may be varied relative to each other within a pre-determined range as and when required.
Regarding claim 5, Schoeley teaches that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018].
Schoeley does not teach that the first twin-screw extruder (4) is a co-rotating twin-screw extruder, an intermeshing twin-screw extruder, or a co-rotating and intermeshing twin-screw extruder. However, Mount teaches that different models of twin-screw extruders have two parallel screw shafts that either rotate in the same direction, called corotating, or rotate in opposite directions, called counterrotating, with varying distance between the screw shafts (p. 236-237), and that this results in screw configurations that range from fully intermeshing to nonintermeshing (p. 237). Schoeley and Mount are analogous art because both references are in the same field of endeavor of a continuous method that uses a twin-screw extruder, or Schoeley and Mount are reasonably pertinent to the problem of selecting types of twin-screw extruders for a continuous method. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to select a twin-screw extruder having two parallel screw shafts that rotate in the same direction that are corotating and that range from fully intermeshing to nonintermeshing, a twin-screw extruder having two parallel screw shafts that rotate in opposite directions that are counterrotating and that are intermeshing, or a twin-screw extruder having two parallel screw shafts that rotate in the same direction that are corotating and that are intermeshing as Schoeley’s twin-screw extruder. The proposed modification would read on wherein the first twin-screw extruder (4) is a co-rotating twin-screw extruder, an intermeshing twin-screw extruder, or a co-rotating and intermeshing twin-screw extruder as claimed. One of ordinary skill in the art would have been motivated to do so because Mount teaches that different models of twin-screw extruders have two parallel screw shafts that either rotate in the same direction, called corotating, or rotate in opposite directions, called counterrotating, with varying distance between the screw shafts (p. 236-237), that this results in screw configurations that range from fully intermeshing to nonintermeshing (p. 237), that corotating twin-screw extruders are used for compounding resin with a wide assortment of additives (p. 237), that counterrotating twin screws are used for compounding other resin systems (p. 238), and that nonintermeshing counterrotating extruders are principally used for devolatilization and chemical reactions (p. 238), which would have been desirable for Schoeley’s twin-screw extruder because Schoeley teaches that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], and curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035].
Regarding claim 6, Schoeley teaches that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018].
Schoeley does not teach that the first twin-screw extruder (4) has an axial length (L) to screw diameter (D) ratio of from 25 : 1 to 65: 1. However, Mount teaches that material in an extruder experiences a range of residence times based on the screw design, type of twin-screw extruder, length to diameter (L/D) ratio, screw speed, and feed rate (p. 243), that barrel sections like extruders come in different length to diameter ratios (L/D) (p. 244), that typical lengths depend on the screw diameter and the manufacturers of the different extruders (p. 244), and that some common L/Ds are 2.5, 3, 4, 5, 6, 8, 10, and 12 (p. 244). Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to optimize the length to diameter of the screw of Schoeley’s twin-screw extruder to be from 25:1 to 65:1. The proposed modification would read on wherein the first twin-screw extruder (4) has an axial length (L) to screw diameter (D) ratio of from 25 : 1 to 65: 1 as claimed. One of ordinary skill in the art would have been motivated to do so because it would have been beneficial for optimizing the desired residence time for Schoeley’s method because Mount teaches that material in an extruder experiences a range of residence times based on the screw design, type of twin-screw extruder, length to diameter (L/D) ratio, screw speed, and feed rate (p. 243), that barrel sections like extruders come in different length to diameter ratios (L/D) (p. 244), that typical lengths depend on the screw diameter and the manufacturers of the different extruders (p. 244), and that some common L/Ds are 2.5, 3, 4, 5, 6, 8, 10, and 12 (p. 244), and because Schoeley teaches that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], that the mixture, after the silica is incorporated into the mixture, is kneaded for 1 h [0034], and that a second kneading is done for 1 h [0034], which means that the length to diameter of the screw of Schoeley’s twin-screw extruder would have affected the desired residence time for Schoeley’s method.
Regarding claim 8, Schoeley teaches that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], and curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035], which optionally reads on in step (f), introduction of additional amounts of component (C) and component (D) and introduction of additional amounts of component (A).
Schoeley does not teach that in step (f) there is provided first and second additional entry ports (28), and wherein the first additional entry port is utilized for the introduction of additional amounts component (C) and optionally component (D) and the second additional entry port is utilized for the introduction of additional amounts of component (A). However, Mount teaches that in a twin-screw extruder, one feed port is located at the rear of the extruder in the first barrel section, and that additional feed streams can be added in numerous locations along the barrel length (p. 238). Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to carry out a second of Schoeley’s hydrophobic treatment with hexamethyldisilazane and water during or after Schoeley’s step of doing a second kneading by adding Schoeley’s hexamethyldisilazane and Schoeley’s water through a second feed port in Schoeley’s twin-screw extruder, and to add more of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane through a third feed port in Schoeley’s twin-screw extruder, as suggested by Mount. The proposed modification would read on wherein in step (f) there is provided first and second additional entry ports (28), and wherein the first additional entry port is utilized for the introduction of additional amounts component (C) and component (D) and the second additional entry port is utilized for the introduction of additional amounts of component (A) as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], and curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035], and because Mount teaches that in a twin-screw extruder, one feed port is located at the rear of the extruder in the first barrel section, and that additional feed streams can be added in numerous locations along the barrel length (p. 238), which means that the proposed modification would have been beneficial for modifying the effectiveness of Schoeley’s hydrophobic treatment of the surface of the silica, for providing a means for adding more of Schoeley’s hexamethyldisilazane and Schoeley’s water, for diluting Schoeley’s mixture with more of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane, and for providing a means for adding more of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane.
Regarding claim 9, Schoeley teaches that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], and curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035], which optionally reads on in step (f), introduction of additional amounts of component (C) and component (D) and introduction of additional amounts of component (A).
Schoeley does not teach that component (C), and component (D) when present, is/are pre-mixed in a second static mixer (31) prior to being introduced through the first additional entry port (28). However, Mount teaches that in a twin-screw extruder, one feed port is located at the rear of the extruder in the first barrel section, and that additional feed streams can be added in numerous locations along the barrel length (p. 238). Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to carry out a second of Schoeley’s hydrophobic treatment with hexamethyldisilazane and water during or after Schoeley’s step of doing a second kneading by adding Schoeley’s hexamethyldisilazane and Schoeley’s water to Schoeley’s two-shaft kneader to knead them to form a mixture, to add the mixture through a second feed port in Schoeley’s twin-screw extruder, and to add more of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane through a third feed port in Schoeley’s twin-screw extruder, as suggested by Mount. The proposed modification would read on wherein component (C), and component (D) when present, is/are pre-mixed in a second static mixer (31) prior to being introduced through the first additional entry port (28) as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that the hexamethyldisilazane [0034] is an organosilicon compound which is reactive with respect to the surface of the silica [0024], that the reactive compound is used for hydrophobic treatment of the surface of the silica [0023], that when using silazanes, it is customary to work in the presence of water [0024], that it is necessary to carry out at least one hydrophobic treatment with the at least one reactive compound suitable for the surface treatment of the silica [0023], that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, devolatilizing at 160° C for 1 h [0034], rediluting the mixture obtained with dimethylvinylsiloxyl-terminated polydimethylsiloxane, obtaining a viscosity of the mixture that is 150 Pa·s [0034], and curing the mixture with a crosslinking component consisting of dimethylvinylsiloxyl-terminated polydimethylsiloxane, Pt catalyst, and dimethylhydrogensiloxyl-terminated polydimethylsiloxane [0035], and because Mount teaches that in a twin-screw extruder, one feed port is located at the rear of the extruder in the first barrel section, and that additional feed streams can be added in numerous locations along the barrel length (p. 238), which means that the proposed modification would have been beneficial for modifying the effectiveness of Schoeley’s hydrophobic treatment of the surface of the silica, for providing a means for adding more of Schoeley’s hexamethyldisilazane and Schoeley’s water, for diluting Schoeley’s mixture with more of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane, and for providing a means for adding more of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane.
Regarding claim 11, Schoeley teaches that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, and devolatilizing at 160° C for 1 h [0034], wherein incorporation of the silica into the mixture can be carried out batchwise in a two-screw kneader [0018], wherein incorporation of the silica into the mixture can be carried out at room temperature or elevated temperature and at sub-atmospheric or super-atmospheric pressures [0018], wherein the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], which suggests further mixing Schoeley’s mixture in Schoeley’s two-shaft kneader after removing Schoeley’s mixture from the twin-screw extruder and before Schoeley’s step of devolatilizing, which suggests wherein residence zone (17) is controlled at a pressure of greater than 0 kPa, and at a temperature of 130° C, and wherein the average residence time in the residence zone (17) is greater than 0 minutes.
Schoeley does not teach that residence zone (17) is controlled at a pressure of between 300 and 2,000 kPa, and at a temperature of between 90 and 170 ° C, and wherein the average residence time in the residence zone (17) is from 5 to 30 minutes. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to, after removing Schoeley’s mixture from the twin-screw extruder, further mix Schoeley’s mixture in another of Schoeley’s two-shaft kneader before Schoeley’s step of devolatilizing, to optimize the pressure of the further mixing to be between 300 and 2,000 kPa, to optimize the temperature of the further mixing to be between 90 and 170 ° C, and to optimize the time of the further mixing to be from 5 to 30 minutes. The proposed modification would read on wherein residence zone (17) is controlled at a pressure of between 300 and 2,000 kPa, and at a temperature of between 90 and 170 ° C, and wherein the average residence time in the residence zone (17) is from 5 to 30 minutes as claimed. One of ordinary skill in the art would have been motivated to do so because Schoeley teaches that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], kneading the mixture at 130° C for 1 hour, adding hexamethyldisilazane and water to the mixture obtained this way, doing a second kneading at 130° C for 1 h, and devolatilizing at 160° C for 1 h [0034], that incorporation of the silica into the mixture can be carried out batchwise in a two-screw kneader [0018], that incorporation of the silica into the mixture can be carried out at room temperature or elevated temperature and at sub-atmospheric or super-atmospheric pressures [0018], and that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], which means that the proposed modification would have improved uniformity of mixing of Schoeley’s mixture before Schoeley’s step of devolatilizing, and which means that the pressure of the further mixing in kPa, the temperature of the further mixing in ° C, and the time of the further mixing in minutes would have affected uniformity of mixing of Schoeley’s mixture before Schoeley’s step of devolatilizing, which means that optimizing the pressure of the further mixing in kPa, the temperature of the further mixing in ° C, and the time of the further mixing in minutes would have been beneficial for optimizing uniformity of mixing of Schoeley’s mixture before Schoeley’s step of devolatilizing.
Regarding claim 12, Schoeley teaches that the method comprises devolatilizing at 160° C for 1 h [0034], wherein the devolatilizing removes the hexamethyldisiloxane and the volatile compounds and is in vacuo [0028], which is by vacuum [0013], which reads on wherein step (e) is undertaken in a stripping device (19), designed to vacuum strip volatiles and gases from the unstripped silicone rubber base composition resulting from step (d).
Schoeley does not teach that step (e) is undertaken in a continuous stripping device (19), designed to vacuum strip volatiles and gases from the unstripped silicone rubber base composition resulting from step (d). However, Mount teaches that high-speed corotating twin-screw extruders are used for devolatilization to remove solvents (p. 237), that nonintermeshing counterrotating extruders are principally used for devolatilization (p. 238), and that a vent stack can be connected to a vacuum port to remove a higher level of volatiles through vacuum venting (p. 244). Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to carry out Schoeley’s step of devolatilizing at 160° C for 1 h in vacuo by vacuum in a high-speed corotating twin-screw extruder or a nonintermeshing counterrotating extruder, wherein a vent stack in the extruder is connected to a vacuum port, such that Schoeley’s hexamethyldisiloxane and volatile compounds are removed, as suggested by Mount. The proposed modification would read on wherein step (e) is undertaken in a continuous stripping device (19), designed to vacuum strip volatiles and gases from the unstripped silicone rubber base composition resulting from step (d) as claimed. One of ordinary skill in the art would have been motivated to do so because Mount teaches that high-speed corotating twin-screw extruders are beneficial for devolatilization to remove solvents (p. 237), that nonintermeshing counterrotating extruders are beneficial for devolatilization (p. 238), and that a vent stack connected to a vacuum port is beneficial for removing a higher level of volatiles through vacuum venting (p. 244), which would have been desirable for Schoeley’s method because Schoeley teaches that the method comprises devolatilizing at 160° C for 1 h [0034], wherein the devolatilizing removes the hexamethyldisiloxane and the volatile compounds and is in vacuo [0028], which is by vacuum [0013].
Regarding claim 13, Schoeley teaches that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018].
Schoeley does not teach that one or more temperature sensors, flow rate sensors, pressure sensors and other instrumentation and/or sensors, are utilized during the method. However, Mount teaches that most extruders are equipped with both a rupture disk and high-pressure (p. 262) sensor that will shut the extruder down in the event of high-pressure situations (p. 263). Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to equip Schoeley’s twin-screw extruder with both a rupture disk and high-pressure sensor that will shut the extruder down in the event of high-pressure situations. The proposed modification would read on wherein one or more pressure sensors are utilized during the method as claimed. One of ordinary skill in the art would have been motivated to do so because Mount teaches that most extruders are equipped with both a rupture disk and high-pressure (p. 262) sensor that will shut the extruder down in the event of high-pressure situations (p. 263), which would have been beneficial for preventing an explosion of Schoeley’s twin-screw extruder caused by high pressure during Schoeley’s method, which would have been desirable for Schoeley’s method because Schoeley teaches that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018].
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Schoeley et al. (EP 0849330 A2, cited in IDS, machine translation in English used for citation, made of record on 12/15/2023) in view of Mount (Mount, 2017, Applied Plastics Engineering Handbook - Processing, Materials, and Applications, 2nd Edition, - 12 Extrusion Processes, Elsevier, Retrieved from https://app.knovel.com/hotlink/pdf/id:kt011DYC4T/applied-plastics-engineering/twin-screw-extruder-equipment) as applied to claim 1, and further in view of Basu (Basu, Swapan, 2019, Plant Flow Measurement and Control Handbook - Fluid, Solid, Slurry and Multiphase Flow - 6. Mass Flow Meter, Elsevier, Retrieved from https://app.knovel.com/hotlink/pdf/id:kt0120UMU5/plant-flow-measurement/mass-flow-meter).
Regarding claim 3, Schoeley in view of Mount renders obvious the continuous method for the preparation of a silicone rubber base composition in accordance with claim 1 as explained above.
Schoeley does not teach that components (C) and (A), and optionally component (D), are pumped into the first static mixer (25) by one or more weight loss meters, mass flow meters, gear pumps, syringe pumps, or piston pumps, or a combination thereof. However, Basu teaches that in most industrial plants mass flow information is preferred in technical processes for cost, material, and mass balance calculations (p. 541), that as mass flow measurements are deployed for the most critical flow measurement applications in a processing plant, the reliability and performance of the mass flow meter is very important and critical (p. 541), that to get the mass flow, it is necessary to accelerate the fluid in a rotating system and measure the inertia effects (p. 541), and that the mass flow meter is used for mass flow measurement (p. 542). Schoeley and Basu are analogous art because both references are in the same field of endeavor of processing of chemical compositions or Schoeley and Basu are reasonably pertinent to the problem of introducing a chemical into a chemical process. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to use at least one mass flow meter to accelerate Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane, Schoeley’s hexamethyldisilazane, and Schoeley’s water through at least one mass flow meter into Schoeley’s two-shaft kneader and to measure their mass flow, as suggested by Basu. The proposed modification would read on components (C) and (A), and optionally component (D), are pumped into the first static mixer (25) by one or more mass flow meters as claimed. One of ordinary skill in the art would have been motivated to do so because Basu teaches that in most industrial plants mass flow information is preferred in technical processes for cost, material, and mass balance calculations (p. 541), that as mass flow measurements are deployed for the most critical flow measurement applications in a processing plant, the reliability and performance of the mass flow meter is very important and critical (p. 541), that to get the mass flow, it is necessary to accelerate the fluid in a rotating system and measure the inertia effects (p. 541), and that the mass flow meter is used for mass flow measurement (p. 542), which means that the proposed modification would have been beneficial for improving an ability for one of ordinary skill in the art to perform cost, material, and mass balance calculations in Schoeley’s method, and for allowing one of ordinary skill in the art to measure the mass flow rate of Schoeley’s dimethylvinylsiloxyl-terminated polydimethylsiloxane, Schoeley’s hexamethyldisilazane, and Schoeley’s water into Schoeley’s two-shaft kneader.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Schoeley et al. (EP 0849330 A2, cited in IDS, machine translation in English used for citation, made of record on 12/15/2023) in view of Mount (Mount, 2017, Applied Plastics Engineering Handbook - Processing, Materials, and Applications, 2nd Edition, - 12 Extrusion Processes, Elsevier, Retrieved from https://app.knovel.com/hotlink/pdf/id:kt011DYC4T/applied-plastics-engineering/twin-screw-extruder-equipment) as applied to claim 1, and further in view of Schneck et al. (Schenck, 2011, Chemical Engineering in the Pharmaceutical Industry - R&D to Manufacturing - 42 Achieving a Hot Melt Extrusion Design Space for the Production of Solid Solutions, John Wiley & Sons, Retrieved from https://app.knovel.com/hotlink/pdf/id:kt012XD6K2/chemical-engineering/material-feeding).
Regarding claim 7, Schoeley in view of Mount renders obvious the continuous method for the preparation of a silicone rubber base composition in accordance with claim 1 as explained above. Schoeley teaches that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], wherein the mixture is present in a two-shaft kneader [0028], and that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018].
Schoeley does not teach that component (B) is fed to the reinforcing filler (B) entry port (27) at a constant rate by a continuous feeder for powder selected from one or more tables, belts, loss in weight feeders, side feeds, feed enhancement technology systems, or screws. However, Schenck teaches extruder feed systems that are gravimetric feeders that are for feeding solids to the extruder (p. 822), that constant flow rates into the extruder are attained via loss in weight feedback control (p. 823), and that a loss in weight feeder delivers powder gravimetrically to volumetric conveyors coupled to the side of the extruder (p. 823). Schoeley and Schenck are analogous art because both references are in the same field of endeavor of a continuous method that uses a twin-screw extruder and that feeds powder into a process, or Schoeley and Schenck are reasonably pertinent to the problem of feeding powder into a process in a twin-screw extruder. Before the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to use a loss in weight feeder to incorporate Schoeley’s silica into Schoeley’s mixture in Schoeley’s twin-screw extruder, as suggested by Schenck. The proposed modification would read on wherein component (B) is fed to the reinforcing filler (B) entry port (27) at a constant rate by a continuous feeder for powder selected from loss in weight feeders as claimed. One of ordinary skill in the art would have been motivated to do so because Schenck teaches that a loss in weight feeder is beneficial for delivering powder gravimetrically to volumetric conveyors coupled to the side of an extruder (p. 823), and that loss in weight feedback control is beneficial for attaining constant flow rates into an extruder (p. 823), which would have been desirable for Schoeley’s method because Schoeley teaches that the method comprises incorporating silica into a mixture of dimethylvinylsiloxyl-terminated polydimethylsiloxane and hexamethyldisiloxane [0034], and that the process can also be carried out in continuously operating mixing units, such as a twin-screw extruder [0018], and since Schoeley’s silica is a powder, feeding it into a twin-screw extruder would have required a feeder for delivering powder to an extruder and would have required a constant flow rate.
Correspondence
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/DAVID T KARST/Primary Examiner, Art Unit 1767