CN104194881A - Composition for double clutch gearbox oil, use of composition and lubricating oil comprising composition - Google Patents
Composition for double clutch gearbox oil, use of composition and lubricating oil comprising composition Download PDFInfo
- Publication number
- CN104194881A CN104194881A CN201410389865.1A CN201410389865A CN104194881A CN 104194881 A CN104194881 A CN 104194881A CN 201410389865 A CN201410389865 A CN 201410389865A CN 104194881 A CN104194881 A CN 104194881A
- Authority
- CN
- China
- Prior art keywords
- oil
- composition
- lubricating oil
- clutch gearbox
- ionic liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
The invention relates to a composition for double clutch gearbox oil. The composition comprises the following components in parts by mass: 0.5-15 parts of viscosity index improver, 0.05-10 parts of friction improver and 0.1-10 parts of ionic liquid. The invention further relates to use of the composition and wet type double clutch gearbox lubricating oil comprising the composition. The composition provided by the invention can satisfy the lubricating requirements of clutches, a synchronizer, a gear and a bearing in a wet type double clutch gearbox, and thus can be used for the wet type double clutch gearbox lubricating oil. The lubricating oil has excellent low temperature performance, frictional characteristic, performance of the synchronizer and rust and corrosion resistance. Compared with similar marketed products, the lubricating oil added with the composition has a remarkable advantage in wearing endurance and is simple in ingredients and simple and convenient in manufacturing process.
Description
Technical field
The present invention relates to lubricating oil field, be specifically related to a kind of composition for two clutch gearbox oil, its purposes, and the lubricating oil that comprises it.
Background technology
Along with people are to driving improving constantly of the aspect requirements such as comfort, discharge, fuel economy, double clutch gearbox (DCT) is developed rapidly.Due to the unique texture of DCT, also lubricating oil has been proposed to higher requirement simultaneously.
As dry dual clutch wheel box, its lubrication needs is consistent with traditional manual transmission oil product.And as wet-type dual-clutch gear box oil, due to the difference of gearbox designs and oiling system, its lubricating oil has very unique feature and effect.To in a series of requirements of oil product, there is antagonism in the two clutch gearboxes of wet type, this carrys out these demands that mutually oppose of balance with regard to requiring the two clutch gearbox oil of wet type to have unique performance, thereby makes the performance of wheel box reach optimum between part.The concrete effect of the two clutch gearbox oil of wet type comprises lubricated clutch coupling, gear unit, main shaft, bearing and synchronizer; Hydraulic pressure as clutch coupling replacing and gear unit gear shift is carried out medium; Reduce gear unit wearing and tearing, wheel box parts played to rust protection protection simultaneously; Can provide heat radiation etc. for whole system.
DCTF oil product must have excellent high temperature performance to keep good temperature pumping to ensure wheel box oil product at lower temperature, simultaneously at high temperature or under high-load, still can protect wheel box parts.Humid clutch is undoubtedly the most important key part of DCT, and the accurate control of clutch coupling is of crucial importance for the smooth operation of wheel box.DCTF oil product must within the drain period, (in the shift process of about 2,000,000 times) be consistent starting characteristic and anti-jitter weather resistance, wherein suitable rubbing characteristics and the friction weather resistance of oil product are vital for gearshift quality level and smooth gearshift and lasting for these.For the synchronizer parts in DCT, also need the rubbing characteristics of DCTF product, oil product must maintain specific frictional coefficient in 5000 loop tests conventionally, and not significantly wearing and tearing.Gear in double clutch gearbox is generally twisted spur gear, and the stress that each gear bears is greater than the sun and planet gear in traditional automatic gear-box, and extreme pressure, the abrasion resistant qualities of therefore oil product being had relatively high expectations reduce the galling producing in gear unit engagement process.In double clutch working process, surface temperature can be up to hundreds of degree Celsius, the acidic by-products that oil product thermo-cracking produces can form paint film or greasy filth, affects the work of hydraulic valve and the work of clutch coupling, and therefore oil product must have excellent heat and oxidative stability.Oil product will play rust resistance and corrosion resistance characteristic to the steel part in wheel box and copper part; especially to the copper ring in wheel box wherein; due to the extreme pressure protection of having emphasized gear, and extreme pressure agent in formula easily causes the corrosion of copper part, therefore also should be noted the balance of formula.DCTF product contacts with a lot of parts in whole wet-type dual-clutch wheel box, require except routine with the compatibility of rubber, sealing material, in DCT, also emphasize the rly. contacting with oil product, the consistency of sensor electronic unit, avoid these parts to produce deterioration effect, have influence on the optimum reaction times, or cause leakage.
No matter require from above-mentioned these, be clearly traditional automatic transmission fluid (ATF), or the manual transmission hydraulic efficiency oil (MTF) of standard all cannot be born the important task of protection DCT.DCT special lube (DCTF), if will ensure the technical superiority of DCT and the weather resistance of use, just need to adopt specific formula technique.
Summary of the invention
For overcoming the defect of existing DCTF oil property aspect, find the lubricating oil of a kind of DCT of being specially adapted to, the object of this invention is to provide a kind of composition that becomes case oil for two clutches.
Another object of the present invention is to provide the purposes of described composition.
Another object of the present invention is to provide the two clutch gearbox lubricating oil of a kind of wet type.
Provided by the invention pair of clutch becomes case oil compositions, comprises by mass parts:
Viscosity index improver: 0.5～15 part;
Friction improver: 0.05～10 part;
Ionic liquid: 0.1～10 part.
Preferably, described composition comprises by mass parts:
Viscosity index improver: 5～12 parts;
Friction improver: 0.1～5 part;
Ionic liquid: 1～5 part.
More preferably, described composition comprises by mass parts:
Viscosity index improver: 5～10 parts;
Friction improver: 0.1～3 part;
Ionic liquid: 1～3 part.
In composition described in technique scheme, described viscosity index improver is selected from described viscosity index improver and is selected from molecular weight and is less than the polymethacrylate (PMA) that 1000 polyisobutene (PIB) and/or molecular weight are 200～2000.
In composition described in technique scheme, described friction improver is selected from one or more in the acid phosphorous acid ester of monoalkyl long-chain, monoalkyl long-chain acid phosphoric acid ester, polyol esters of fatty acids, boronation polyol esters of fatty acids.
Preferably, described friction improver is selected from one or more in octadecyl phosphorous acid ester, octadecyl phosphoric acid ester, oleic acid glycerine ester, boronation oleic acid glycerine ester.
In composition described in technique scheme, described ionic liquid can be this area common ion liquid such as glyoxaline ion liquid, quaternary phosphonium class ionic liquid, quaternary amines ionic liquid, is preferably one or more in alkyl substituted imidazole molybdate ion liquid, alkyl substituted imidazole tetrafluoroborate ion liquid, alkyl replacement hexafluorophosphate ionic liquid, alkyl replacement season phosphonium salt class ionic liquid.
The present invention also provides the purposes of composition in the two clutch gearbox lubricating oil of wet type described in technique scheme any one.
The invention provides the two clutch gearbox lubricating oil of a kind of wet type, comprise base oil, wherein, described lubricating oil also comprises the composition described in 5～20% technique scheme any one by mass percentage; Preferably 10～15%.
In the two clutch gearbox lubricating oil of wet type described in technique scheme, described base oil is selected from mineral oil and/or synthetic base oil.
Preferably, described mineral oil is selected from III class mineral oil; Described synthetic base oil is selected from one or more in PAO synthetic oil, synthetic ester lubricant, polyethers synthetic oil.
More preferably, to make gained lubricating oil have the requirement of best low-temperature performance in order meeting, to have best athletics simultaneously, described base oil is the mixture of PAO synthetic oil and III class mineral oil.
Described III class mineral oil is III class hydrogenation mineral oil.According to API normalized definition, III class mineral oil basis oil is mainly hydroisomerizing base oil, and sulphur content is less than or equal to 0.03%, and saturated hydrocarbon content is more than or equal to 90%, and viscosity index is greater than 120.Described III class mineral oil includes but not limited to III class hydrogenated base oil, the III class base oil of S-oil production or the III class base oil that Yubase produces that China Petrochemical Industry's high bridge is produced.
Described synthetic ester lubricant includes but not limited to binary synthetic ester lubricant, polyvalent alcohol synthetic ester lubricant etc.
Described lubricating oil also comprises one or more in pour point depressant, anti-wear agent, high-temperature antioxidant, ashless dispersant, metal detergent, metal passivator.The additives such as described pour point depressant, anti-wear agent can adopt any kind in existing lubricating oil additive, and addition can require to be determined by those skilled in the art according to lubricants performance.
Preferably, described lubricating oil parts by weights comprises:
Composition provided by the invention can meet the lubricating requirement of clutch coupling, synchronizer, gear and bearing in wet-type dual-clutch wheel box, therefore can be used for the lubricating oil of the two clutch gearboxes of wet type, gained lubricating oil has good low-temperature performance, rubbing characteristics, synchronizer performance, antirust, anti-corrosive performance, has passed through LVFA test, SAE No.2 experiment of friction performance, the synchronous weather resistance bench testing of SSP-180.Add the lubricating oil and the comparison of similar commercially available prod of composition of the present invention, aspect friction endurance quality, there is significant advantage, and composition has been simple, manufacturing process is easy.
Brief description of the drawings
Fig. 1 is two clutch gearbox oil of embodiment 1～4 and the SAE#2 rub(bing)test comparison diagram of commercially available prod.
Embodiment
Following examples are used for illustrating the present invention, but are not used for limiting the scope of the invention.If do not specialize, in embodiment, reagent used is conventional commercial reagent, the conventional means that in embodiment, technique means used is well known to those skilled in the art.
The present invention tests to evaluate the performance of two clutch gearbox oil compositionss by SAE No.2 rub(bing)test, FZG SSP180 synchronizer test and LVFA low speed friction.
SAE No.2 rub(bing)test: the gearshift performance of automatic transmission fluid, is mainly reflected in the relation of kinetic friction coefficient and static friction coefficient, μ 0/ μ d representative gearshift performance.
FZG SSP180 synchronizer test: SSP180 can, for measuring the synchronizer of unlike material, can measure frictional coefficient, the synchronizer wear pattern after how many times circulates, and the life-span of synchronizer.
LVFA low speed friction test: the anti-jitter performance of automatic transmission fluid, characterizes with LVFA low speed friction experimental data d μ/dv.Measuring d μ/dv numerical value, to be greater than time of 0 longer, shows that the anti-jitter performance of ATF is better.
The preparation method of composition of embodiment of the present invention is: first base oil (A) joined and is in harmonious proportion in still, and heated and stirred to 30～50 DEG C; Then add friction improver (C), synthermal lower stirring 20～40 minutes; Add again viscosity index improver (B) and optional pour point depressant, be warming up to 70～90 DEG C and stir 70～100 minutes; Be cooled to approximately 50～60 DEG C, add ionic liquid (D), synthermal lower stirring 10～30 minutes; Finally add other components such as optional anti-wear agent, high-temperature antioxidant, ashless dispersant, metal detergent and metal passivator, continue to stir 100～150 minutes to mixture homogeneous transparent and get final product.
Embodiment 1
The composition (mass percent) of two clutch gearbox oil compositionss is as follows: base oil (4cSt III class base oil in mass ratio: 3cSt III class base oil=1: 2.3) 77.9%, viscosity index improver (PMA in mass ratio: PIB=6.2: 2.0) 8.2%, the two octadecyl phosphorous acid esters 1.2% of friction improver, 3-n-octylcyclam-methyl-imidazoles molybdate ion liquid 2.5%, other composition: pour point depressant polymethacrylate 2.0%, anti-wear agent trialkyl phosphorodithioate 1.0%, the different monooctyl ester 0.5% of high-temperature antioxidant second, n-butyl dithiocarbamate, ashless dispersant polyisobutenyl succimide 6.0%, metal detergent alkyl benzene calcium sulfonate 0.2%, metal passivator thiadiazoles stearylamine formaldehyde condensation products 0.5%.
Embodiment 2
Two clutch gearbox oil compositionss composed as follows: base oil (4cSt III class base oil in mass ratio: 3cSt III class base oil: PAO4=1: 2.2: 0.5) 75.8%, viscosity index improver PMA9.4%, friction improver boronation list oleic acid glycerine ester 2.0%, tributyl alkyl quaternary phosphonium ionic liquid 3.0%, other composition: the different monooctyl ester 1.8% of pour point depressant second, n-butyl dithiocarbamate, anti-wear agent phosphorodithioic acid acrylate 1.0%, the two butyl pentanoic 0.5% of high-temperature antioxidant, ashless dispersant polyisobutenyl succimide 5.8%, metal detergent alkyl benzene calcium sulfonate 0.2%, metal passivator thiadiazoles stearylamine formaldehyde condensation products 0.5%.
Embodiment 3
Two clutch gearbox oil compositionss composed as follows: base oil 4cSt III class base oil 78.3%, viscosity index improver PMA8.0%, the two oleic acid glycerine esters 0.2% of friction improver, methyl imidazolium tetrafluoroborate ionic liquid 3.0%, other composition: pour point depressant poly-methyl acrylate 2.0%, anti-wear agent phosphorodithioic acid acrylate 1.0%, the two butyl pentanoic 0.5% of high-temperature antioxidant, ashless dispersant polyisobutenyl succimide 6.0%, metal detergent alkyl benzene calcium sulfonate 0.5%, metal passivator thiadiazoles stearylamine formaldehyde condensation products 0.5%.
Embodiment 4
Two clutch gearbox oil compositionss composed as follows: base oil (4cSt III class base oil in mass ratio: 3cSt III class base oil: PAO4=1: 2.2: 0.5) 78.0%, viscosity index improver PMA8.0%, friction improver list octadecyl phosphorous acid ester 1.8%, 1-butyl-3-Methylimidazole hexafluorophosphate ionic liquid 2.5%, other composition: pour point depressant polymethacrylate 1.8%, anti-wear agent phosphorodithioic acid acrylate 1.0%, the two butyl pentanoic 0.5% of high-temperature antioxidant, ashless dispersant polyisobutenyl succimide 5.8%, metal detergent alkyl benzene calcium sulfonate 0.2%, metal passivator thiadiazoles stearylamine formaldehyde condensation products 0.4%.
Embodiment 1～4 is compared as follows with commercially available pair of clutch gearbox oil production key characteristic:
Conclusion:
Adopt two clutch gearbox oil that composition provided by the invention makes to there is good rubbing characteristics, synchronizer performance, antiseptic property, pass through LVFA test, SAE No.2 experiment of friction performance, the synchronous weather resistance bench testing of SSP-180, can meet the lubricating requirement of clutch coupling, synchronizer, gear and bearing in wet-type dual-clutch wheel box., compare with commercially available prod meanwhile, particularly rub aspect endurance quality and there is obvious advantage in frictional behaviour.
Although above the present invention is described in detail with a general description of the specific embodiments, on basis of the present invention, can make some modifications or improvements it, this will be apparent to those skilled in the art.Therefore, these modifications or improvements without departing from theon the basis of the spirit of the present invention, all belong to the scope of protection of present invention.
Claims (10)
1. a composition that becomes case oil for two clutches, is characterized in that, comprises by mass parts:
Viscosity index improver: 0.5～15 part;
Friction improver: 0.05～10 part;
Ionic liquid: 0.1～10 part.
2. composition according to claim 1, is characterized in that, described composition comprises by mass parts:
Viscosity index improver: 5～12 parts;
Friction improver: 0.1～5 part;
Ionic liquid: 1～5 part.
3. composition according to claim 1 and 2, is characterized in that, described viscosity index improver is selected from molecular weight and is less than the polymethacrylate that 1000 polyisobutene and/or molecular weight are 200～2000.
4. composition according to claim 1 and 2, is characterized in that, described friction improver is selected from one or more in the acid phosphorous acid ester of monoalkyl long-chain, monoalkyl long-chain acid phosphoric acid ester, polyol esters of fatty acids, expanded polyol esters of fatty acids.
5. composition according to claim 4, is characterized in that, described friction improver is selected from one or more in octadecyl phosphorous acid ester, octadecyl phosphoric acid ester, oleic acid glycerine ester, boronation oleic acid glycerine ester.
6. composition according to claim 1 and 2, it is characterized in that, described ionic liquid is selected from one or more in alkyl substituted imidazole molybdate ion liquid, alkyl substituted imidazole tetrafluoroborate ion liquid, alkyl replacement hexafluorophosphate ionic liquid, alkyl replacement season phosphonium salt class ionic liquid.
7. the purposes of composition in the two clutch gearbox lubricating oil of wet type described in claim 1-6 any one.
8. the two clutch gearbox lubricating oil of wet type, comprises base oil, it is characterized in that, described lubricating oil also comprises the composition described in 5～20% claim 1-6 any one by mass percentage; Preferably 10～15%.
9. lubricating oil according to claim 8, is characterized in that, described base oil is selected from mineral oil and/or synthetic base oil; Preferably, described mineral oil is selected from III class mineral oil; Described synthetic base oil is selected from one or more in PAO synthetic oil, synthetic ester lubricant, polyethers synthetic oil.
10. lubricating oil according to claim 8 or claim 9, is characterized in that, described lubricating oil also comprises one or more in pour point depressant, anti-wear agent, high-temperature antioxidant, ashless dispersant, metal detergent, metal passivator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410389865.1A CN104194881A (en) | 2014-08-08 | 2014-08-08 | Composition for double clutch gearbox oil, use of composition and lubricating oil comprising composition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410389865.1A CN104194881A (en) | 2014-08-08 | 2014-08-08 | Composition for double clutch gearbox oil, use of composition and lubricating oil comprising composition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104194881A true CN104194881A (en) | 2014-12-10 |
Family
ID=52080252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410389865.1A Pending CN104194881A (en) | 2014-08-08 | 2014-08-08 | Composition for double clutch gearbox oil, use of composition and lubricating oil comprising composition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104194881A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106967485A (en) * | 2017-03-31 | 2017-07-21 | 烟台德高石油有限公司 | Gear box oil and preparation method for the composition and preparation method of hybrid electric vehicle gearshift case oil and comprising said composition |
| CN108026473A (en) * | 2015-07-20 | 2018-05-11 | 路博润公司 | Without zinc lubricating composition |
| CN111621355A (en) * | 2019-02-28 | 2020-09-04 | 大林产业株式会社 | Lubricant composition for gear oil |
| DE102020203358A1 (en) | 2020-03-16 | 2021-09-16 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein | Wet-running, switchable friction clutch, motor vehicle with such a friction clutch, as well as methods for operating the friction clutch |
| CN113930273A (en) * | 2020-06-29 | 2022-01-14 | 中国石油化工股份有限公司 | Lubricating oil composition for DHT structure gearbox and application thereof |
| CN117402666A (en) * | 2023-10-23 | 2024-01-16 | 众联晟通(苏州)科技有限公司 | Lubricating protective agent for automobile engine and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101149125A (en) * | 2006-09-21 | 2008-03-26 | 日产自动车株式会社 | Low-friction sliding mechanism and uses thereof |
| CN102766507A (en) * | 2011-05-06 | 2012-11-07 | 中国石油天然气股份有限公司 | Lubricant composition for double-clutch gearbox |
-
2014
- 2014-08-08 CN CN201410389865.1A patent/CN104194881A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101149125A (en) * | 2006-09-21 | 2008-03-26 | 日产自动车株式会社 | Low-friction sliding mechanism and uses thereof |
| CN102766507A (en) * | 2011-05-06 | 2012-11-07 | 中国石油天然气股份有限公司 | Lubricant composition for double-clutch gearbox |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108026473A (en) * | 2015-07-20 | 2018-05-11 | 路博润公司 | Without zinc lubricating composition |
| CN106967485A (en) * | 2017-03-31 | 2017-07-21 | 烟台德高石油有限公司 | Gear box oil and preparation method for the composition and preparation method of hybrid electric vehicle gearshift case oil and comprising said composition |
| CN111621355A (en) * | 2019-02-28 | 2020-09-04 | 大林产业株式会社 | Lubricant composition for gear oil |
| CN111621355B (en) * | 2019-02-28 | 2022-06-21 | Dl化学株式会社 | Lubricant composition for gear oil |
| DE102020203358A1 (en) | 2020-03-16 | 2021-09-16 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein | Wet-running, switchable friction clutch, motor vehicle with such a friction clutch, as well as methods for operating the friction clutch |
| DE102020203358B4 (en) | 2020-03-16 | 2022-12-22 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein | Wet-running, switchable friction clutch, motor vehicle with such a friction clutch, and method for operating the friction clutch |
| CN113930273A (en) * | 2020-06-29 | 2022-01-14 | 中国石油化工股份有限公司 | Lubricating oil composition for DHT structure gearbox and application thereof |
| CN117402666A (en) * | 2023-10-23 | 2024-01-16 | 众联晟通(苏州)科技有限公司 | Lubricating protective agent for automobile engine and preparation method thereof |
| CN117402666B (en) * | 2023-10-23 | 2024-04-16 | 众联晟通(苏州)科技有限公司 | Lubricating protective agent for automobile engine and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104194881A (en) | Composition for double clutch gearbox oil, use of composition and lubricating oil comprising composition | |
| CN102766507B (en) | Lubricant composition for double-clutch gearbox | |
| CN105176641B (en) | A kind of lubricant oil composite and preparation method thereof of tractor three | |
| JP5693240B2 (en) | Lubricating oil composition | |
| CN106967483A (en) | A kind of stable friction performance lubricant oil composite | |
| CN104583379A (en) | Lubricant compositions | |
| CN102807908A (en) | Wide temperature range polyol ester lubricating oil composition suitable for aircraft engine | |
| CN103103007B (en) | Automatic gear box oil composition | |
| CN103695136A (en) | All-purpose lubricating oil for motor and gear case of mini-tiller | |
| JP6159107B2 (en) | Lubricating oil composition | |
| CN105038914A (en) | Gearbox lubricating agent composition and preparation method thereof | |
| CN106010758A (en) | Lubricating oil for automotive mechanical gears and preparation method of lubricating oil | |
| JP6219203B2 (en) | Lubricating oil composition for agricultural machinery | |
| CN105273820A (en) | Lubricating oil with high abrasion resistance | |
| CN105296115A (en) | Subway train special gear oil and preparation method | |
| CN102311846B (en) | High-temperature-resistant universal extreme-pressure grease lubricant and preparation method thereof | |
| CN102277226B (en) | Hydrodynamic drive lubricating oil composition for engineering plant | |
| KR20110059308A (en) | A mixture of manual transmission fluid | |
| CN108085102A (en) | Automatic transmission fluid | |
| JP5301304B2 (en) | Lubricating oil composition for continuously variable transmission | |
| CN107201263A (en) | Hydraulic transmission oil | |
| JP2017155193A (en) | Lubricant composition, lubrication method, and gearbox | |
| CN104099161A (en) | Lubricating oil composition for antiskid differential | |
| RU2627766C1 (en) | High-temperature multi-purpose universal lubricant | |
| Boran et al. | Rheological behavior of castor oil mixed with different pyromellitic esters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20141210 |
|
| RJ01 | Rejection of invention patent application after publication |