CN101195516B - Low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and technique of preparing the same - Google Patents
Low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and technique of preparing the same Download PDFInfo
- Publication number
- CN101195516B CN101195516B CN2006101368139A CN200610136813A CN101195516B CN 101195516 B CN101195516 B CN 101195516B CN 2006101368139 A CN2006101368139 A CN 2006101368139A CN 200610136813 A CN200610136813 A CN 200610136813A CN 101195516 B CN101195516 B CN 101195516B
- Authority
- CN
- China
- Prior art keywords
- glass
- sealing
- high temperature
- temperature
- glass powder
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Glass Compositions (AREA)
Abstract
The invention relates to low-melting point and lead-free microcrystalline glass for closure of a high temperature electrothermal tube and a process for preparation thereof. The component is Bi2O3-SiO2-B2O3-Al2O3-CaO microcrystalline glass. The weight percentages of the each oxide component are that Bi2O3: 20-70%, SiO2: 10-30%, B2O3: 1-15%, Al2O3: 5-30%, CaO: 1-30%, ZrO2: 1-10%, TiO2: 1-10% and ZnO: 1-10%. The process for preparation comprises: weighing Bi2O3, SiO2, Al2O3 and the like according to the weight percentage and mixing sufficiently, melting the mixture for 1-6 hours at a temperature of 1200 DEG C-1600 DEG C, then quenching the mixture with water, cooling and solidifying and ball grinding to microcrystalline glass powder; pelleting the microcrystalline glass powder, modeling and dumping, performing vacuum sealing for various high temperature electrothermal tubes at a temperature of 800 DEG C-900 DEG C. The invention has good wear-resistance and corrosion resistance, high strength, has no environmental pollution component, can directly realize nontoxic and pollution-free seal for the high temperature electrothermaltube, and have wide application.
Description
Technical field
The present invention relates to a kind of leadless crystallizing glass and preparation technology thereof, particularly a kind of be widely used in the having low melting point, high expand of various stainless steel pipe high temperature electric heating tube sealing-in, nontoxic, pollution-free devitrified glass and this devitrified glass and preparation technology.
Background technology
In the empty production process of burning with elevated temperature heat fulgurite goods, need to adopt fusing point lower, the glass powder of the coefficient of expansion and stainless steel coupling is as joint filling material.
The quality of high temperature electric heating tube product performance, whether work-ing life is permanent, depends on the Sealling Technique and the joint filling material of electrothermal tube to a great extent.Before this, domestic electrothermal tube manufacturing enterprise uses the joint filling material of glue class cakingagents such as Resins, epoxy as electrothermal tube for a long time always.Use this class joint filling material, product is easily aging, and the insulation values of sealing descends, and performance often can not get the approval of world market, and product can't export the world market in a large number.Now in the world popular employing be devitrified glass as joint filling material, the seal glass pottery all contains Pb0 traditionally.Japan, European Union and the U.S. etc. have made laws, and China has also drafted file, forbids behind the 1-3 that the household electrical appliance seal, sealing materials contains PbO.The glass that seals of electrothermal tube requires its specific conductivity low in addition, sealing-in place good insulation preformance, some at present domestic barium crown sealed glass pottery documents, because of containing K, alkalimetal ions such as Na, specific conductivity is all generally higher, has therefore become the problem that must solve as early as possible for elevated temperature heat fulgurite production provides the glass that seals not leaded, high-insulativity.
At present, existing in the world seal glass and glass powder have following several usually.
Philips company has with SiO
2System is main barium crown sealed glass, China Patent No. CN1088895A; The coefficient of expansion can reach 9.2 * 10
-6/ ℃; But softening temperature T
SoftHigher, reach about 650 ℃, require to drop to about 500 ℃ log (rho)
250=8.85, log (rho)
350=7.00, require under the normal temperature to be mainly used in the sealing-in of vacuum glass about resistivity decreased to 5.
There are the barium crown sealed glass patent of SnO system, China Patent No. 1087773 in Corning Incorporated; Sealing temperature is 430~500 ℃, and resistivity is higher, owing to contain a large amount of SnO in the glass powder, is easy to oxidation, need produce and sealing-in under nitrogen reducing atmosphere condition, thereby be difficult to carry out industrialization and follow-up sealing-in application.
The spy of Hitachi opens flat 2-267137 and discloses a class vanadium oxide (V
2O
5) be glass, the coefficient of expansion of this glass is 90 * 10
-7/ ℃ below, sealing temperature is below 400 ℃, it mainly acts on is to prepare the coefficient of expansion in (30~45) * 10
-7/ ℃ about seal glass, but in this product, plumbous oxide is as the neccessary composition of component, thereby can't satisfy unleaded requirement.
In the research of barium crown sealed glass, also have and adopt bismuth oxide to substitute the bismuth glass of plumbous oxide, there are several Bi in Japan
2O
3The barium crown sealed glass patent of system, but poor repeatability.Bi
2O
3System is serious to corrosion of crucible, changes the condition harshness of glass; Viscosity is low near the fusing point; Easily crystallization is difficult for into glass.
In above-mentioned many requirements of the seal glass of Unlead low-smelting point high expansion coefficient, seal with seal glass based on the elevated temperature heat fulgurite and can't satisfy mostly.
Summary of the invention
Technical problem to be solved by this invention is: solve the problem that above-mentioned prior art exists, and provide a kind of sealing strength height, insulating property and environmental-protecting performance is good and the low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and the preparation technology thereof that are complementary with elevated temperature heat fulgurite stainless steel pipe, the melting temperature of this low-melting point leadless crystallizing glass, the coefficient of expansion can mate adjustment according to the product performance of the high temperature electric heating tube tubing of required sealing-in, and then reach sealing-in effect preferably, simultaneously, this seal glass does not contain pollution, highly toxic substances such as lead.This preparation technology's method not only can make the manufacturing processed of seal glass simple and direct, and can be according to characteristic, the requirement of electrothermal tube different metal materials, adjust every set of dispense ratio flexibly, satisfy of the different requirements of different metal material elevated temperature heat fulgurite product seal glass temperature of fusion, the coefficient of expansion.
The technical solution used in the present invention is:
This low-melting point leadless crystallizing glass for sealing high temperature electric heating tube, it is at least by bismuth oxide (Bi
2O
3), aluminum oxide (Al
2O
3) and silicon oxide (SiO
2) mutually mix after, form glass powder through fusion, cooling, pulverizing, pass through granulation, moulding and sintering again, be prepared into the elevated temperature heat fulgurite and seal and use devitrified glass.
In the technique scheme, solid components of the present invention is Bi
2O
3-SiO
2-B
2O
3-Al
2O
3-CaO microcrystalline glass in series, the mass percentage content of each oxide compound are Bi
2O
3: 20~70%, SiO
2: 10~30%, B
2O
3: 1~15%, Al
2O
3: 5~30%, CaO:1~30%, ZrO
2: 1~10%, TiO
2: 1~10%, ZnO:1~10%.
The preparation technology of this low-melting point leadless crystallizing glass for sealing high temperature electric heating tube is:
1) weighing following raw materials according by mass percentage: Bi
2O
3: 20~70%, SiO
2: 10~30%, B
2O
3: 1~15%, Al
2O
3: 5~30%, CaO:1~30%, ZrO
2: 1~10%, TiO
2: 1~10%, ZnO:1~10%, thorough mixing in mixer is made compound; Compound is placed the high-temperature electric resistance furnace melting, and smelting temperature is 1200~1600 ℃, and soaking time is 1~6 hour;
2) behind the fusing fluid shrend cooling curing to compound in the step 1), be placed on the ball mill ball milling and make the host glass powder, obtain the micro mist that particle diameter is not more than 5 microns by screening;
3) granulation of glass powder: mass percent 95% dehydrated alcohol adds the dissolving of 5% ethyl cellulose and is prepared into organic binder bond under 80 ℃ of water bath condition, and above-mentioned glass powder is added 5% organic binder bond, and dispersed with stirring is carried out granulation then, and 325 orders sieve;
4) pressed compact moulding and binder removal: to the glass granulation compound moulding in harder that makes in the step 3), forming pressure is 3~5 tons; The moulding sample carries out binder removal to organic binder bond under 250~600 ℃, soaking time is 0.5~1 hour;
5) the good devitrified glass of binder removal carries out vacuum seal at the stainless steel pipe sealing high temperature electric heating tube vacuum seal: to above-mentioned steps 4), and sealing temperature is 800~900 ℃.
The present invention passes through the analysis to basic demands such as physics, chemical property and the technology of various stainless steel pipe sealing high temperature electric heating tubes usefulness devitrified glasses, environmental protection, as the sealing-in between metal-metal, the macromolecular material non-refractory, need select glass-ceramic for use in higher class occasion, therefore select for use devitrified glass as joint filling material.By to Bi
2O
3-SiO
2-B
2O
3-Al
2O
3Systematic studyes such as-CaO microcrystalline glass in series the coefficient of expansion, second-order transition temperature, softening temperature, crystallite forming core growth dynamics, determine microcrystalline glass formula and melting, ball-milling technology, make it to satisfy and the basic demand of elevated temperature heat fulgurite with various stainless steel pipe couplings and good combination: the coefficient of expansion is enough high to mate with metal, temperatures involved metallic substance during the low as far as possible in order to avoid sealing-in of fusing point, therefore require it to make devitrified glass, to obtain to have wear resistance, intensity preferably, erosion resistance etc.
Secondly, do not contain the composition that environment is polluted easily in the barium crown sealed glass provided by the present invention, can directly carry out nontoxic, pollution-free sealing-in, and the processing and manufacturing process is simple and direct, is suitable for suitability for industrialized production the elevated temperature heat fulgurite that needs sealing-in.
In addition, the high expansion coefficient bismuth oxide (Bi by different content
2O
3) adjust the unleaded coefficient of expansion that seals glass, so, barium crown sealed glass provided by the present invention can also according to the sealing-in goods coefficient of expansion do not coexist in a big way in adjust, thereby can adapt to and satisfy the different sealing-in requirements of multiple metal pipe material high temperature thermionic valves, for example various stainless steels, the intermetallic sealing-in of INCO.Utilize the glass powder of specific composition to be pressed into certain shape,, become the elevated temperature heat fulgurite seal, sealing materials of stable performance through special thermal treatment technology.
Description of drawings
Fig. 1 is a manufacturing process flow diagram of the present invention.
Embodiment
Embodiment 1:
The devitrified glass that is used for the sealing-in of SUS304 series stainless steel elevated temperature heat fulgurite
1, microcrystalline glass formula: Bi
2O
3: SiO 41%,
2: B 32%,
2O
3: Al 3%,
2O
3: 12%, CaO:4%, ZnO:6%, ZrO
2: 2%;
2, glass melting technology: 1200 ℃ fusing is after 6 hours down, and shrend cooling back forms the glass fragment;
3, ball milling and granularity control: to glass fragment corase grind, the back is finely ground to maximum particle diameter with planetary ball mill or agitating ball mill and is no more than 5 microns with vibromill;
4, the sintering of devitrified glass: will contain the 5wt% ethyl cellulose and be dissolved in and be prepared into organic binder bond in the dehydrated alcohol, above-mentioned glass powder is added 5% organic binder bond, dispersed with stirring is carried out granulation then, 325 orders sieve, compound moulding in harder after will sieving then, forming pressure is 3 tons; Under 250 ℃ organic binder bond in the moulding sample is carried out binder removal, temperature rise rate is 5 ℃/min, and soaking time is 1 hour;
4, vacuum seal.The good devitrified glass of above-mentioned binder removal sealed at SUS304 stainless steel pipe elevated temperature heat electrothermal tube carry out vacuum seal, sealing temperature is 800 ℃;
5, the electric property after devitrified glass carries out vacuum seal in SUS304 series stainless steel elevated temperature heat fulgurite:
The softening point temperature scope of this seal glass is 500 ℃, and the thermal expansivity scope is 75 * 10
-7/ ℃, the cold insulation resistance value after the sealing-in is greater than 10
5M Ω, greater than 10M Ω, the cold conditions withstand voltage is greater than 1800V/5mA/3s for hot insulation resistance value (it is stable to be energized to the thermionic valves surface temperature with voltage rating, cuts off the power supply immediately for measuring insulation values in 15 seconds), and leakage current is less than 0.5mA.
Embodiment 2:
The devitrified glass that is used for the sealing-in of SUS310S series stainless steel elevated temperature heat fulgurite
1, microcrystalline glass formula: Bi
2O
3: SiO 53%,
2: B 20%,
2O
3: Al 4%,
2O
3: 3%, CaO:4%, TiO
2: ZnO:12% 6%;
2, glass melting technology: 1600 ℃ fusing is after 3 hours down, and shrend cooling back forms the glass fragment;
3, ball milling and granularity control: to glass fragment corase grind, the back is finely ground to maximum particle diameter with planetary ball mill or agitating ball mill and is no more than 5 microns with vibromill;
4, the sintering of devitrified glass: will contain the 5wt% ethyl cellulose and be dissolved in and be prepared into organic binder bond in the dehydrated alcohol, above-mentioned glass powder is added 5% organic binder bond, dispersed with stirring is carried out granulation then, 325 orders sieve, compound moulding in harder after will sieving then, forming pressure is 3 tons; Under 500 ℃ organic binder bond in the moulding sample is carried out binder removal, temperature rise rate is 5 ℃/min, and soaking time is 0.5 hour;
4, vacuum seal.The good devitrified glass of above-mentioned binder removal sealed at SUS304 stainless steel pipe elevated temperature heat electrothermal tube carry out vacuum seal, sealing temperature is 850 ℃;
5, the electric property after devitrified glass carries out vacuum seal in SUS310S series stainless steel elevated temperature heat fulgurite:
The softening point temperature scope of this seal glass is 550 ℃, and the thermal expansivity scope is 80 * 10
-7/ ℃, the cold insulation resistance value after the sealing-in is greater than 10
5M Ω, greater than 10M Ω, the cold conditions withstand voltage is greater than 1800V/5mA/3s for hot insulation resistance value (be energized to the tube-surface temperature-stable with voltage rating, cutting off the power supply immediately measured insulation values in 15 seconds), and leakage current is less than 0.5mA.
Embodiment 3:
The devitrified glass that is used for the sealing-in of SUS310S series stainless steel elevated temperature heat fulgurite
2, microcrystalline glass formula: Bi
2O
3: SiO 53%,
2: B 20%,
2O
3: Al 4%,
2O
3: 3%, CaO:4%, TiO
2: ZnO:12% 6%;
2, glass melting technology: 1600 ℃ fusing is after 1 hour down, and shrend cooling back forms the glass fragment;
3, ball milling and granularity control: to glass fragment corase grind, the back is finely ground to maximum particle diameter with planetary ball mill or agitating ball mill and is no more than 5 microns with vibromill;
4, the sintering of devitrified glass: will contain the 5wt% ethyl cellulose and be dissolved in and be prepared into organic binder bond in the dehydrated alcohol, above-mentioned glass powder is added 5% organic binder bond, dispersed with stirring is carried out granulation then, 325 orders sieve, compound moulding in harder after will sieving then, forming pressure is 5 tons; Under 600 ℃ organic binder bond in the moulding sample is carried out binder removal, temperature rise rate is 5 ℃/min, and soaking time is 0.5 hour;
4, vacuum seal.The good devitrified glass of above-mentioned binder removal sealed at SUS304 stainless steel pipe elevated temperature heat electrothermal tube carry out vacuum seal, sealing temperature is 900 ℃;
5, the electric property after devitrified glass carries out vacuum seal in SUS310S series stainless steel elevated temperature heat fulgurite:
The softening point temperature scope of this seal glass is 550 ℃, and the thermal expansivity scope is 80 * 10
-7/ ℃, the cold insulation resistance value after the sealing-in is greater than 10
5M Ω, greater than 10M Ω, the cold conditions withstand voltage is greater than 1800V/5mA/3s for hot insulation resistance value (be energized to the tube-surface temperature-stable with voltage rating, cutting off the power supply immediately measured insulation values in 15 seconds), and leakage current is less than 0.5mA.
Claims (1)
1. the preparation technology of a low-melting point leadless crystallizing glass for sealing high temperature electric heating tube is characterized in that:
1) weighing following raw materials according by mass percentage: Bi
2O
3: 20~70%, SiO
2: 10~30%, B
2O
3: 1~15%, Al
2O
3: 5~30%, CaO:1~30%, ZrO
2: 1~10%, TiO
2: 1~10%, ZnO:1~10%, thorough mixing in mixer is made compound; Compound is placed the high-temperature electric resistance furnace melting, and smelting temperature is 1200~1600 ℃, and soaking time is 1~6 hour;
2) behind the fusing fluid shrend cooling curing to the compound in the step 1), be placed on the ball mill ball milling and make the host glass powder, obtain the micro mist that particle diameter is not more than 5 microns by screening;
3) granulation of glass powder: mass percent 95% dehydrated alcohol adds the dissolving of 5% ethyl cellulose and is prepared into organic binder bond under 80 ℃ of water bath condition, and above-mentioned glass powder is added 5% organic binder bond, and dispersed with stirring is carried out granulation then, and 325 orders sieve;
4) pressed compact moulding and binder removal: to the glass granulation compound moulding in harder that makes in the step 3), forming pressure is 3~5 tons; The moulding sample carries out binder removal to organic binder bond under 250~600 ℃, soaking time is 0.5~1 hour;
5) the good devitrified glass of binder removal seals at stainless steel pipe elevated temperature heat electrothermal tube and carries out vacuum seal vacuum seal: to above-mentioned steps 4), and sealing temperature is 800~900 ℃.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2006101368139A CN101195516B (en) | 2006-12-06 | 2006-12-06 | Low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and technique of preparing the same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2006101368139A CN101195516B (en) | 2006-12-06 | 2006-12-06 | Low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and technique of preparing the same |
Publications (2)
Publication Number | Publication Date |
---|---|
CN101195516A CN101195516A (en) | 2008-06-11 |
CN101195516B true CN101195516B (en) | 2011-05-11 |
Family
ID=39546173
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN2006101368139A Expired - Fee Related CN101195516B (en) | 2006-12-06 | 2006-12-06 | Low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and technique of preparing the same |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN101195516B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102992632A (en) * | 2012-11-10 | 2013-03-27 | 江苏瑞德新能源科技有限公司 | Lead-free glass powder for aluminium paste of solar cell |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102173576A (en) * | 2011-02-12 | 2011-09-07 | 西安创联宏晟电子有限公司 | Lead-free electronic glass and preparation method thereof |
CN102351403B (en) * | 2011-07-18 | 2013-08-07 | 湖南威能新材料科技有限公司 | Method for preparing ultrafine glass powder used for solar battery slurry |
CN103693854B (en) * | 2013-12-06 | 2016-03-09 | 王卫霞 | A kind of Unlead low-smelting point microcrystalline glass powder and preparation method thereof |
CN105461241A (en) * | 2015-12-24 | 2016-04-06 | 永新电子常熟有限公司 | Preparation method of high temperature-resisting electronic linkage |
CN106568465A (en) * | 2016-03-04 | 2017-04-19 | 北京玻璃研究院 | Method for packaging metal coated fiber grating |
CN109836046A (en) * | 2017-11-29 | 2019-06-04 | 辽宁法库陶瓷工程技术研究中心 | A kind of glass and its method for sealing for aluminium silicon carbide device sealing sealing-in |
CN108328929A (en) * | 2018-03-06 | 2018-07-27 | 厦门百嘉祥微晶材料科技股份有限公司 | A kind of high-temperature high-insulation glass and preparation method thereof for electric heating pipe port sealing-in |
CN109928639A (en) * | 2019-01-31 | 2019-06-25 | 无锡麦格拉斯新材料有限公司 | A kind of glass ceramic composite and preparation method thereof for protecting metallic surface |
CN110963669B (en) * | 2019-12-31 | 2021-05-28 | 中建材蚌埠玻璃工业设计研究院有限公司 | Glass raw material pretreatment granulation process |
CN111484254B (en) * | 2020-04-22 | 2022-07-05 | 中国建筑材料科学研究总院有限公司 | High-temperature sealing glass and preparation method and application thereof |
CN112047631A (en) * | 2020-08-25 | 2020-12-08 | 广东风华高新科技股份有限公司 | Lead-free low-temperature sintering encapsulation glass slurry and preparation method thereof |
-
2006
- 2006-12-06 CN CN2006101368139A patent/CN101195516B/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102992632A (en) * | 2012-11-10 | 2013-03-27 | 江苏瑞德新能源科技有限公司 | Lead-free glass powder for aluminium paste of solar cell |
CN102992632B (en) * | 2012-11-10 | 2015-01-07 | 江苏瑞德新能源科技有限公司 | Lead-free glass powder for aluminium paste of solar cell |
Also Published As
Publication number | Publication date |
---|---|
CN101195516A (en) | 2008-06-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN101195516B (en) | Low-melting point leadless crystallizing glass for sealing high temperature electric heating tube and technique of preparing the same | |
KR100978359B1 (en) | Lead-free glass material for use in sealing and, sealed article and method for sealing using the same | |
US4405722A (en) | Sealing glass compositions | |
KR970000898B1 (en) | Non-lead sealing glasses | |
CN101456674B (en) | Rare-earth doped leadless and low-melting point sealing glass and its preparation method | |
CN1772676B (en) | Low melting glass, sealing composition and sealing paste | |
CN101066840B (en) | No-lead RE doped sealing glass powder with low smelting point and its production process | |
CN101113073B (en) | Leadless low-melting glass powder for seal with metal or alloy and preparation method thereof | |
CN101633560A (en) | Lead-free low-melting-point glass and preparation method thereof | |
CN106587641A (en) | Low-melting-point glass powder and laser-illumination glass ceramic made from low-melting-point glass powder | |
CN103626398B (en) | A kind of crystallization type lead-free low-temperature seal glass and preparation thereof and using method | |
CN111138081A (en) | Improved preparation method of glass sealing material | |
CN103601369A (en) | Preparation method of lead-free electronic glass powder for back aluminum slurry of solar cell | |
CN101602573A (en) | A kind of bismuthate lead-free sealing glass material with low melting point and preparation method thereof | |
JP3339647B2 (en) | Lead-free low melting glass and sealing glass composition | |
CN102603195A (en) | Lead-free glass powder for solar electrode sizing agent and preparation method thereof | |
CN103319097A (en) | Low temperature lead-free glass dust and preparation method thereof | |
CN109455940A (en) | A kind of soft lead-free low-temperature seal glass and preparation method thereof | |
CN114477768A (en) | Lead-free low-melting-point sealing glass doped with fusible metal alloy and preparation method thereof | |
JP2006290665A (en) | Lead-free sealing glass powder and its producing method | |
CN1116612A (en) | Glass solder for sealing and its preparing method | |
CN104891803A (en) | Bi system lead-free low-melting glass powder for conductive paste and preparation method thereof | |
CN101376563A (en) | Low-melting glass containing nano zinc oxide and preparation thereof | |
CN102757182A (en) | Low-temperature low expansion coefficient high-rigidity lead-free electronic glass powder and preparation method thereof | |
US4131478A (en) | Sealing glass compositions and method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
C17 | Cessation of patent right | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110511 Termination date: 20111206 |