CN101214941A - Method for producing microcapsule tricalcium phosphate - Google Patents
Method for producing microcapsule tricalcium phosphate Download PDFInfo
- Publication number
- CN101214941A CN101214941A CNA200710066501XA CN200710066501A CN101214941A CN 101214941 A CN101214941 A CN 101214941A CN A200710066501X A CNA200710066501X A CN A200710066501XA CN 200710066501 A CN200710066501 A CN 200710066501A CN 101214941 A CN101214941 A CN 101214941A
- Authority
- CN
- China
- Prior art keywords
- tricalcium phosphate
- salt
- microcapsule
- acid
- metal oxide
- 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.)
- Granted
Links
Landscapes
- Glass Compositions (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
The invention provides a process for producing microcapsule tricalcium phosphate. Firstly, preparing the tricalcium phosphate into slurry, and then preparing nonferrous metal salts with solubility into microcapsule fluid and mixing the slurry and the microcapsule fluid, adjusting the pH value of reaction fluid to 9-11, and then aging from 10 minutes to 2 hours under agitation, after filtering, rinsing filter cakes 2-3 times, drying and breaking up the filter cakes to obtain the microencapsule tricalcium phosphate production, thereby forming oxide layer or hydroxide layer of nonferrous metal on the surface of the tricalcium phosphate, when putting the products into frit to heat together under high temperature, the invention can be changed into oxide of nonferrous metal, thereby improving milkiness effect, and can be compared with opacifier of oxides of pure microencapsulation metal, and the costs are only half of the opacifier of oxides of pure microencapsulation metal, even only one third, being capable of replacing the oxides of pure microencapsulation metal completely. The invention has the advantages of simple technique, low costs and consumption, perfect property, low price, stable quality, non contaminant discharging, energy saving and environmental protection.
Description
Technical field
The present invention relates to a kind of method of microcapsule tricalcium phosphate, belong to technical field of inorganic chemical industry.
Background technology
Opacifying agent is the important component of producing ceramic glaze and opaque glass, also opacifying agent is called opalizer usually.The opacifying agent that uses has two classes at present: a class is the opacifying agent that contains the non-ferrous metal element, as stannic oxide, titanium oxide, weisspiessglanz, zinc oxide and zirconium white etc.Another kind of is alkali earth metal phosphate, as bone meal, and tricalcium phosphate, hydroxy phosphorus Calx etc.In ceramic glaze, its opaque effect of opacifying agent that contains non-ferrous metal is better, uses comparatively extensively, but price is comparatively expensive; Its opaque effect of phosphatic opacifying agent is relatively poor, and range of application is limited, and some non-ferrous metal element also is with negative impacts such as carcinogenic, that the nuclear radiation amount exceeds standard simultaneously, should use cautiously.For a long time, people are accustomed to use and contain the phosphatic opacifying agent of bone meal, and its main component is a tricalcium phosphate, derives from the product of animal skeleton behind high-temperature calcination, and its resource is very limited.But the tricalcium phosphate of synthetic or hydroxyapatite then are bone meal substitutes preferably.According to the literature, the method for synthetic tricalcium phosphate roughly is divided three classes:
(1) be the liquid phase neutralisation of raw material with calcium hydroxide, phosphoric acid, its reaction formula is:
3Ca(OH)
2+2H
3PO
4→Ca
3(PO
4)
2↓+6H
2O
(2) be the liquid phase double decomposition of raw material with phosphoric acid salt and soluble calcium salt, its reaction formula is:
2Na
3PO
4+3CaCl
2→Ca
3(PO
4)
2↓+6NaCl
(3) be the high-temperature synthesis of raw material with a kind of phosphorus source in secondary calcium phosphate, monocalcium phosphate, calcium oxide, calcium hydroxide, the lime carbonate and a kind of calcium, its reaction formula is:
2CaHPO
4+CaO→Ca
3(PO
4)
2↓+H
2O
2CaHPO
4+Ca(OH)
2→Ca
3(PO
4)
2↓+2H
2O
2CaHPO
4+CaCO
3→Ca
3(PO
4)
2↓+CO
2↑+H
2O
In the aforesaid method, the method for (2) is comparatively expensive because of soluble calcium salt and phosphoric acid salt, and produces salt bearing liquid wastes, handles comparatively difficulty; (3) method exists the problem of high energy consumption because of reacting being higher than under 1000 ℃ of high temperature, is subjected to bigger restriction economically; Comprehensive aspects factor, the method for (1) are comparatively economical, so also be the method that extensively adopts in the industrial production.But no matter be the bone meal or the tricalcium phosphate of synthetic, in the glaze sintering procedure, more or less can with some the composition generation chemical reaction in the glaze, such as with glaze in silicon dioxde reaction, generate the strong calcium silicate glass body of light transmission, thereby reduce the shading performance of glaze, influence opaque effect.Just because of this, restricted the development of bone meal or tricalcium phosphate class glaze opacifying agent.
Summary of the invention
Poor for the opacifying property that overcomes the existence of bone meal of the prior art or tricalcium phosphate class glaze opacifying agent, deficiencies such as opaque effect difference the invention provides a kind of method of producing microcapsule tricalcium phosphate.
The present invention realizes by following technical proposal: a kind of method of producing microcapsule tricalcium phosphate is characterized in that comprising following process steps:
The preparation of A, tricalcium phosphate slip: phosphoric acid is added drop-wise in the lime slurry or the tricresyl phosphate calcium powder is added in the water, stir, and control reaction solution pH value is 9～11, obtain concentration and be 5～40% tricalcium phosphate slip;
The preparation of B, microcapsule liquid: the soluble salt of non-ferrous metal is soluble in water, form uniform concentration and be 10～20% the aqueous solution;
C, the aqueous solution of step B gained is joined in the tricalcium phosphate slip of steps A gained, the aqueous solution add-on of step B gained is counted 0.5～15% of mass ratio with metal oxide, and be benchmark with 100 parts of tricalcium phosphate quality, stirring and adjusting the reaction solution pH value is 9～11, the tricalcium phosphate particle surface is coated deposit non-ferrous metal oxide skin or hydroxide layer, afterwards battle arrayization 10 minutes～2 hours under agitation;
D, its surface of step C gained is coated with the tricalcium phosphate of non-ferrous metal oxide skin or hydroxide layer, after filtering, filter cake washed 2～3 times after, filter cake is carried out drying, pulverizing, the microcapsule tricalcium phosphate product.
The non-ferrous metal soluble salt of described B step is one or more in pink salt, zinc salt, titanium salt, zirconates, antimonic salt, stannate, zincate, the stibnate, after forming corresponding nonferrous metal oxides layer or hydroxide layer on the tricalcium phosphate surface, when in participating in glaze, together carrying out heat, become corresponding oxide compound, thereby produce and the similar opaque effect of pure nonferrous metal oxides, to replace expensive pure nonferrous metal oxides, wherein:
Pink salt is one or more in tin protochloride, tin chloride, sodium stannate, the potassium stannate, add-on is counted 0.5～5% of mass ratio with metal oxide, be preferably 1～5%, and be benchmark with 100 parts of tricalcium phosphate quality, addition is lower than at 0.5% o'clock, the opaque effect of tricalcium phosphate in glaze that coats is not obvious, when being higher than 5%,, consume more solubility pink salt though opaque effect is good, cause cost to increase, and filter comparatively difficulty;
Zinc salt is one or more in zinc chloride, zinc sulfate, zinc nitrate, sodium zincate, the potassium zincate, its add-on is counted 1～10% of mass ratio with metal oxide, be preferably 3～8%, and be benchmark with 100 parts of tricalcium phosphate quality, be lower than at 1% o'clock, the opaque effect of the tricalcium phosphate of coating in glaze is not obvious, is higher than at 10% o'clock. and opaque effect is good, but it is, uneconomical because of zinc salt consumption increases production cost greatly;
Lead salt is plumbous oxide, lead sulfate, lead nitrate; Titanium salt is titanium chloride, titanium sulfate, titanium tetrachloride; Zirconates is zirconium chloride, zirconium nitrate; Its add-on is counted 0.5～8% of mass ratio with metal oxide, be preferably 2～6%, and be benchmark with 100 parts of tricalcium phosphate quality, be lower than at 0.5% o'clock, the opaque effect of tricalcium phosphate in glaze that coats is not obvious, being higher than at 8% o'clock. opaque effect is good, but increases production cost greatly because of lead salt consumption.
Will coat deposition nonferrous metal oxides, oxyhydroxide at the tricalcium phosphate particle surface in a word, its concrete add-on depends on the kind of used solubility non-ferrous metal salt.
Described A step tricalcium phosphate pulp density is preferably 8～25%, and the best is 10～16%.
The battle arrayization time of described C step is preferably 15 minutes～and 1 hour, the best is 20～40 minutes.
Described C step tricalcium phosphate slip is preferably 9.5～10.5 at the forward and backward pH value of coating deposition, and the best is 9.8～10.2.
The adjustment of described pH value is with acid or alkali, and wherein acid is with in the nitric acid of mineral acid, phosphoric acid, the hydrochloric acid one or more, perhaps uses in organic acid formic acid, acetate, oxalic acid, the citric acid one or more; In alkali ammoniacal liquor, sodium hydroxide, potassium hydroxide, the calcium hydroxide one or more.
Described A, B, C step are carried out to tricalcium phosphate slip boiling point condition in room temperature, preferably at room temperature carry out.
When described C step was washed filter cake, each leaching requirement and tricalcium phosphate were equal in weight.
By that analogy, the soluble salt of other non-ferrous metal also has effect same.
The present invention has following advantage and effect: adopt such scheme, can form corresponding nonferrous metal oxides layer or hydroxide layer on the tricalcium phosphate surface, when it is participating in when together carrying out heat in the glaze, promptly can be changed into corresponding nonferrous metal oxides, thereby improve its opaque effect, so can compare favourably with the opacifying agent of pure nonferrous metal oxides class, and its cost only is pure nonferrous metal oxides class opacifying agent half, even only be 1/3rd, can replace expensive pure nonferrous metal oxides fully, technology of the present invention is simple, production cost is low, energy consumption is low, non-pollutant discharge, energy-conserving and environment-protective, constant product quality, performance is good, and price is low, is suitable for applying.
Embodiment
Below will be by specific embodiment, and outside the claim protection domain that the present invention advocated with the tricalcium phosphate of ordinary method preparation as a comparison case, the present invention and effect thereof are described further, with further proof the present invention's superiority.In described embodiment, used per-cent is mass percent.
The preparation of microcapsule tricalcium phosphate is to carry out in the conversion unit of following test in following examples: add 500 ml concns in advance and be 12% milk of lime dispersion liquid in 1 liter of glass beaker. be furnished with the agitator of an adjustable speed, make material be able to well blend and dispersion, insert a pH value METHOD FOR CONTINUOUS DETERMINATION instrument in the reaction slurry simultaneously, with the pH value variation of METHOD FOR CONTINUOUS DETERMINATION and observation whole process.
The evaluation of products obtained therefrom adopts following method to carry out in following examples:
The making of standard test piece: parent glaze is taken from the glaze that does not add opacifying agent and tinting material that floor tile factory uses, the zinc oxide opacifying agent of adding 8% mixes in glaze, glazing on the square floor tile biscuit of a 6 * 6cm, after under 120 ℃ of temperature dry 15 minutes, under 1050 ℃ of temperature, fired 30 minutes and cooling.
Test piece of the present invention: with products obtained therefrom in the embodiment of the invention is opacifying agent, join in the parent glaze mix after, adopt method same as described above to be prepared into corresponding test piece.
The contrast test piece:
1, prepare tricalcium phosphate as follows earlier: adding 500 ml concns are 12% lime slurry in 1 liter of glass beaker, dispersed with stirring 5 minutes, progressively drip the phosphoric acid of technical grade 85%, be stabilized in 10 until pH value under agitation, continue to stir 20 minutes after generating the tricalcium phosphate slip, constant the stopping of the value of turning round stirs, and filters, filter cake was in 120 ℃ of dryings 30 minutes, and fragmentation obtains tricalcium phosphate powder 90 grams.
2, with above-mentioned 1 gained tricalcium phosphate as opacifying agent with after basic glaze mixes, adopt the method identical to be prepared into the contrast test piece with above-mentioned standard test piece.
Judge with the visual means contrast that 3, consequently: compare with standard test piece, the opaque effect of contrast test piece is relatively poor.
Embodiment 1
A, to add 500 ml concns in 1 liter of glass beaker in advance be 12% lime slurry. dispersed with stirring 5 minutes, progressively drip the phosphoric acid of technical grade 85% afterwards, be stabilized in 10 until pH value under agitation, continue to stir 20 minutes, generate concentration and be 15% tricalcium phosphate slip;
B, powdery zinc nitrate 10.5 gram is dissolved in 94.5 ml distilled waters, forms uniform concentration and be 10% zinc nitrate aqueous solution;
C, the aqueous solution of step B is joined in the tricalcium phosphate slip of steps A, add-on is in 5% zinc oxide, and be that benchmark is (promptly in concentration is 15% 600 gram tricalcium phosphate slips with 100 parts of tricalcium phosphate quality, adding concentration is 10% zinc nitrate aqueous solution 105 grams), stir and be that 5% ammoniacal liquor adjustment reaction solution pH value is stabilized in 10 with concentration, continue to stir 10～20 minutes, and made the tricalcium phosphate particle surface coat the zinc hydroxide layer, afterwards battle arrayization 40 minutes under agitation;
D, its surface of step C gained is coated with the tricalcium phosphate of zinc hydroxide layer, after the method for prior art is filtered, through wash for 3 times filter cake, each leaching requirement and tricalcium phosphate are equal in weight, with filter cake after under 120 ℃ of temperature dry 300 minutes, pulverize the microcapsule tricalcium phosphate powder-like product.
Above-mentioned entire operation is all at room temperature carried out.
With products obtained therefrom as opacifying agent add in the glaze mix after, make corresponding test piece, compare with standard test piece, its opaque effect is apparently higher than standard test piece.
The preparation process of all the other embodiment 2～9 is identical with embodiment 1, and preparation condition, adds test piece and the standard test piece comparative result that makes in the glaze to as opacifying agent, sees Table 1.
Table 1
| Sequence number | Non-ferrous metal salt kind and concentration | The nonferrous metal oxides add-on | Adjust kind and the concentration of PH | Make the numbering after the test piece | Add amount in the glaze to as opacifying agent | With the standard test piece comparative result |
| 2 | 10% zinc nitrate | 5％ | 5% ammoniacal liquor | A1 B1 C1 | 3％ 6％ 8％ | Close better good |
| 3 | 12% zinc chloride | 6％ | 5% ammoniacal liquor | A2 B2 C2 | 3％ 6％ 8％ | Close better good |
| 4 | 8% sodium zincate | 7％ | 10% nitric acid | A3 B3 C3 | 4％ 8％ 10％ | Close better good |
| 5 | 5% tin chloride | 2.5％ | 5% ammoniacal liquor | A4 B4 C4 | 2％ 6％ 8％ | Difference is close better |
| 6 | 8% sodium stannate | 4％ | 10% nitric acid | A5 B5 C5 | 4％ 6％ 8％ | Close better good |
| 7 | 5% titanium sulfate | 3％ | 5% ammoniacal liquor | A6 B6 C6 | 3％ 5％ 7％ | Close better good |
| 8 | 6% titanium tetrachloride | 5％ | 5% ammoniacal liquor | A7 B7 C7 | 4％ 6％ 8％ | Close better good |
| 9 | 8% zirconium chloride | 5％ | 5% ammoniacal liquor | A8 B8 C8 | 4％ 6％ 8％ | Close better good |
Claims (9)
1. method of producing microcapsule tricalcium phosphate is characterized in that comprising following process steps:
The preparation of A, tricalcium phosphate slip: phosphoric acid is added drop-wise in the lime slurry or the tricresyl phosphate calcium powder is added in the water, stir, and control reaction solution pH value is 9～11, obtain concentration and be 5～40% tricalcium phosphate slip;
The preparation of B, microcapsule liquid: the soluble salt of non-ferrous metal is soluble in water, form uniform concentration and be 10～20% the aqueous solution;
C, the aqueous solution of step B gained is joined in the tricalcium phosphate slip of steps A gained, the aqueous solution add-on of step B gained is counted 0.5～15% of mass ratio with metal oxide, and be benchmark with 100 parts of tricalcium phosphate quality, stirring and adjusting the reaction solution pH value is 9～11, the tricalcium phosphate particle surface is coated deposit non-ferrous metal oxide skin or hydroxide layer, afterwards battle arrayization 10 minutes～2 hours under agitation;
D, its surface of step C gained is coated with the tricalcium phosphate of non-ferrous metal oxide skin or hydroxide layer, after filtering, filter cake washed 2～3 times after, filter cake is carried out drying, pulverizing, the microcapsule tricalcium phosphate product.
2. the method for production microcapsule tricalcium phosphate according to claim 1, the non-ferrous metal soluble salt that it is characterized in that described B step is one or more in pink salt, zinc salt, titanium salt, zirconates, antimonic salt, stannate, zincate, the stibnate, after forming corresponding nonferrous metal oxides layer or hydroxide layer on the tricalcium phosphate surface, when in participating in glaze, together carrying out heat, become corresponding oxide compound, wherein:
Pink salt is one or more in tin protochloride, tin chloride, sodium stannate, the potassium stannate, and add-on is counted 0.5～5% of mass ratio with metal oxide, and is benchmark with 100 parts of tricalcium phosphate quality;
Zinc salt is one or more in zinc chloride, zinc sulfate, zinc nitrate, sodium zincate, the potassium zincate, and its add-on is counted 1～10% of mass ratio with metal oxide, and is benchmark with 100 parts of tricalcium phosphate quality;
Lead salt is plumbous oxide, lead sulfate, lead nitrate; Titanium salt is titanium chloride, titanium sulfate, titanium tetrachloride; Zirconates is zirconium chloride, zirconium nitrate; Its add-on is counted 0.5～8% of mass ratio with metal oxide, and is benchmark with 100 parts of tricalcium phosphate quality.
3. the method for production microcapsule tricalcium phosphate according to claim 3, the add-on that it is characterized in that described pink salt is counted the 1～5% preferable of mass ratio with metal oxide; The add-on of zinc salt is counted the 3～8% preferable of mass ratio with metal oxide; The add-on of lead salt is counted the 2～6% preferable of mass ratio with metal oxide.
4. the method for production microcapsule tricalcium phosphate according to claim 5 is characterized in that described A step tricalcium phosphate pulp density is preferably 8～25%, and the best is 10～16%.
5. the method for production microcapsule tricalcium phosphate according to claim 7 is characterized in that the battle arrayization time of described C step is preferably 15 minutes～1 hour, and the best is 20～40 minutes.
6. the method for production microcapsule tricalcium phosphate according to claim 1 is characterized in that described C step tricalcium phosphate slip is preferably 9.5～10.5 at the forward and backward pH value of coating deposition, and the best is 9.8～10.2.
7. the method for production microcapsule tricalcium phosphate according to claim 1, the adjustment acid or the alkali that it is characterized in that described pH value, wherein acid is with in the nitric acid of mineral acid, phosphoric acid, the hydrochloric acid one or more, perhaps uses in organic acid formic acid, acetate, oxalic acid, the citric acid one or more; In alkali ammoniacal liquor, sodium hydroxide, potassium hydroxide, the calcium hydroxide one or more.
8. the method for production microcapsule tricalcium phosphate according to claim 1 is characterized in that described A, B, C step carry out to tricalcium phosphate slip boiling point condition in room temperature, preferably at room temperature carries out.
9. the method for production microcapsule tricalcium phosphate according to claim 1, when it is characterized in that described C step is washed filter cake, each leaching requirement and tricalcium phosphate are equal in weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200710066501XA CN100572266C (en) | 2007-12-28 | 2007-12-28 | A kind of method of producing microcapsule tricalcium phosphate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB200710066501XA CN100572266C (en) | 2007-12-28 | 2007-12-28 | A kind of method of producing microcapsule tricalcium phosphate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101214941A true CN101214941A (en) | 2008-07-09 |
| CN100572266C CN100572266C (en) | 2009-12-23 |
Family
ID=39621463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB200710066501XA Expired - Fee Related CN100572266C (en) | 2007-12-28 | 2007-12-28 | A kind of method of producing microcapsule tricalcium phosphate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100572266C (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1454640A3 (en) * | 1999-10-15 | 2004-09-22 | Genetics Institute, LLC | Formulations of hyaluronic acid for delivery of osteogenic proteins |
| US6558709B2 (en) * | 2001-01-05 | 2003-05-06 | Howmedica Osteonics Corp. | Calcium phosphate composition and method of preparing same |
| CN100534897C (en) * | 2003-12-18 | 2009-09-02 | 免疫科学株式会社 | Sintered body of titanium compound |
| CN100357178C (en) * | 2005-09-27 | 2007-12-26 | 华南理工大学 | Carbonic acid type high activity partially crystallized calcium phosphate and its prepn |
-
2007
- 2007-12-28 CN CNB200710066501XA patent/CN100572266C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN100572266C (en) | 2009-12-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI527763B (en) | Method for forming basic nickel carbonate | |
| CN100545092C (en) | A kind of preparation method of submicron grade superfine calcium carbonate dispersion particle | |
| CN101250337B (en) | Titania coating kaolinite compound powder and method for preparing same | |
| CN102502742A (en) | Method for preparing high-whiteness aluminium hydroxide micropowder from Bayer process sodium aluminate solution | |
| CN103224717A (en) | Preparation method of composite coating titanium dioxide pigment | |
| CN103011642A (en) | Method for preparing high-strength alpha-type hemihydrate gypsum by utilizing calcium carbide sludge modified phosphogypsum with normal pressure hydrothermal method | |
| CN107352632A (en) | A kind of compound alkali of activity and its preparation method and application | |
| CN103288066A (en) | Method for preparing hydroxyapatite and/or tricalcium phosphate by using gelatin production wastewater | |
| CN103539097A (en) | Preparation method of multi-shape alkaline manganese phosphate microcrystal | |
| CN103058156B (en) | Method for preparing calcium phosphate by utilizing slag charge discharged during sodium hypophosphite preparation | |
| CN102051629B (en) | Method for preparing FexPO4 by electrolyzing ferrophosphorus | |
| CN101708835A (en) | Production method of high-purity zinc phosphate | |
| CN105925822A (en) | Method for processing scheelite concentrate through sulfuric acid to prepare tungstate solution | |
| CN100360429C (en) | Method for decomposing potash feldspar ore by low temperature wet process | |
| CN108070280A (en) | A kind of preparation method of silicon dioxide microsphere-titanium dioxide composite powder pigment | |
| CN105565350B (en) | A kind of method that utilization aluminous fly-ash produces aluminum oxide | |
| CN100572266C (en) | A kind of method of producing microcapsule tricalcium phosphate | |
| CN107674483A (en) | A kind of Ardealite putty powder prepared by ardealite | |
| CN104944399B (en) | The preparation method of hydroxyapatite micro-sphere | |
| US2414974A (en) | Production of ferric orthophosphate | |
| CN105565352B (en) | A kind of method that aluminum oxide is produced with aluminous fly-ash | |
| CN108502911B (en) | Barite purifying and whitening agent and purifying and whitening method thereof | |
| CN106590061A (en) | Calcium-based titanium dioxide pigment and preparation method thereof | |
| CN204162450U (en) | A kind of system preparing ammonium tungstate solution | |
| CN100384720C (en) | Process for preparing modified hydroxy apatite powder |
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: 20091223 Termination date: 20121228 |