CN102344661A - PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as preparation method and application thereof - Google Patents
PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as preparation method and application thereof Download PDFInfo
- Publication number
- CN102344661A CN102344661A CN2011103304274A CN201110330427A CN102344661A CN 102344661 A CN102344661 A CN 102344661A CN 2011103304274 A CN2011103304274 A CN 2011103304274A CN 201110330427 A CN201110330427 A CN 201110330427A CN 102344661 A CN102344661 A CN 102344661A
- Authority
- CN
- China
- Prior art keywords
- engineering plastics
- abs
- abs engineering
- weight
- parts
- 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
Images
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
Abstract
The invention is suitable for the technical field of the engineering plastics and provides PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as a preparation method and application thereof. The PC/ABC engineering plastics comprises PC, ABC, solid-state resorcinol-bis(diphenyl phosphate), a styrene-maleic anhydride copolymer, an antioxidant and an ultraviolet absorber. According to the PC/ABS engineering plastics disclosed by the invention, the mechanical property of the PC/ABS engineering plastics is improved obviously by using the styrene-maleic anhydride copolymer as the compatilizer; for one aspect, the flame retardant property of the PC/ABS engineering plastics is improved, and for the other aspect, the production procedure is simplified by using the solid-state resorcinol-bis(diphenyl phosphate). The preparation method of the PC/ABS engineering plastics disclosed by the invention is simple in operation, low in cost, high in economic benefit, and very suitable for industrial production.
Description
Technical field
The invention belongs to the engineering plastics technical field, relate in particular to a kind of PC/ABS engineering plastics, its preparation method and application.
Background technology
Polycarbonate (PC) is a kind of widely used engineering plastics, and it has mechanical property, thermal property and the electrical property of comprehensive stability, has shock resistance, dimensional stabilizing, heat-resisting simultaneously, and the is transparent excellent properties of Denging.But PC exists price more expensive, and processing flowability is undesirable, and the goods unrelieved stress is big, is prone to stress cracking, is difficult to make shortcomings such as large thin-wall goods, restricts its practical application to a great extent.For PC, (ABS) is cheap for acrylonitrile-butadiene-styrene copolymer, excellent property, and the product surface glossiness is good, is easy to machine-shaping, but thermotolerance is relatively poor.
ABS and PC co-blended aurification are a kind of important means of PC modification, and it makes the PC performance excellent more, thereby have widened the Application Areas of PC.The PC/ABS alloy combines both premium properties, has improved thermotolerance and the tensile strength of ABS on the one hand; Reduce the PC melt viscosity on the other hand, improve processing fluidity, reduce the susceptibility of goods internal stress and notched Izod impact strength.The PC/ABS alloy is widely used in automotive industry (dashboard, inside fitting and wheel cover), household electrical appliance, communication equipment, office equipment etc.
PC is different with the ABS resin solubility parameter, and its consistency depends primarily on rubber content among the ABS.If make alloy that better shock strength arranged, need to select the higher trade mark of rubber content among the ABS, and bigger solubility parameter difference causes the consistency at both interfaces relatively poor between PC and the ABS, needs to add compatilizer and improves.Like the multipolymer (MBS) of methyl methacrylate, effect is best, and shock strength is the highest, but MBS is more expensive, and the same two key compositions of divinyl that all contain with ABS, and weather resistance is relatively poor, to a certain degree limits its application in PC/ABS.
On the other hand, itself has self-extinguishing PC, but with the ABS blend after flame retardant properties reduce greatly, need through adding fire retardant to improve the flame retardant properties of alloy material.For the purpose of safety, also along with the improving constantly of environmental requirement, people have proposed high requirement to the thermotolerance of PC/ABS alloy, and halogen-free flame retardant PC/ABS alloy material has obtained fast development in recent years.For example, bromide fire retardant is to use efficient flame-retarding agent the most widely in present fire retardation PC/ABS alloy, but because its generation toxic substance is more and bigger to performance impact, being replaced by halogen-free flame retardants is a kind of trend; Phosphorus flame retardant at PC/ABS alloy flame retarding efficiency also than higher; Heat-drawn wire influence to material when just hanging down owing to molecular weight is bigger; And exist and separate out and processing problems; Domestic and international application is more to be liquid phosphoric acid ester fire retardant BDP and RDP; Need the special interpolation equipment that increases; Such high-molecular weight organic phosphate flame-retardant dosage is domestic basic also at the experimental stage, and external product is generally more expensive.
In sum; Solid-state fire retardation PC/ABS technology is comparatively rare in the domestic prior art; Cause its alloy property relatively poor, the over-all properties that therefore improves halogen-free flame retardant PC/ABS alloy is very necessary, has crucial meaning for the development that promotes China's new material industry.
Summary of the invention
In view of this, the present invention provides a kind of PC/ABS engineering plastics, solves the technical problem of PC/ABS engineering plastics over-all properties difference in the prior art.
The present invention is achieved in that
A kind of PC/ABS engineering plastics comprise the component of following parts by weight:
Above-mentioned PC/ABS engineering plastics preparation method comprises the steps:
Get the component of following parts by weight:
With the PC drying treatment, the PC after this ABS, solid-state Resorcinol-two (diphenyl phosphoester), styrene-maleic anhydride copolymer, oxidation inhibitor, ultraviolet absorbers and the drying treatment is mixed, obtain first mixture;
This first mixture is extruded processing, obtain the PC/ABS engineering plastics.
The present invention further provides the application of above-mentioned PC/ABS engineering plastics in automobile, electronic product, electrical equipment, engineering goods.
PC/ABS engineering plastics of the present invention through using styrene-maleic anhydride copolymer as compatilizer, make the PC/ABS mechanical performance of engineering plastic significantly promote; Through using solid-state Resorcinol-two (diphenyl phosphoester) to improve the flame retardant properties of PC/ABS engineering plastics on the one hand, simplified production sequence on the other hand.PC/ABS engineering plastics preparation method of the present invention, simple to operate, with low cost, economic benefit is high, is very suitable for suitability for industrialized production.
Description of drawings
Fig. 1 is an embodiment of the invention PC/ABS engineering plastics preparation method schema.
Embodiment
In order to make the object of the invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
The embodiment of the invention provides a kind of PC/ABS engineering plastics, comprises the component of following parts by weight:
Particularly, the unit of the parts by weight in the embodiment of the invention is weight unit commonly used such as gram, kilogram, ton.
Particularly, this PC is meant bisphenol A polycarbonate, its melt flow rate (MFR) be 8～25g/10min (300 ℃, 1.2kg).This PC can be virgin material, also can be the reclaiming material.The parts by weight of this PC are 10～80 parts.This PC is a powdered granule.
Particularly, this ABS is meant acrylonitrile-butadiene-styrene copolymer, and this ABS is a powdered granule, by the high glue ABS powder (high glue powder) that emulsion polymerization is produced, butadiene content 50～70%, median size 180 μ m; The parts by weight of this ABS are 5～60 parts.
Particularly, this solid-state Resorcinol-two (diphenyl phosphoesters) are powdered granule, and phosphorus content is 10.8%, can select Zhejiang Province Wansheng Chemical Co., Ltd's product for use.The parts by weight of this solid-state Resorcinol-two (diphenyl phosphoesters) are 5～40 parts, are preferably 10～20.Through selecting for use Resorcinol-two (diphenyl phosphoesters) as fire retardant; The flame retardant properties of PC/ABS engineering plastics is improved greatly; Contain RDP (when the PC/ABS engineering plastics of Resorcinol-two (diphenyl phosphoester) are subjected to high temperature; RDP decomposes the oxygen acid that generates phosphorus; The heat absorption of promotion hydroxy-containing compounds is dehydrated into the charcoal reaction to be carried out, and generates the coke layer of graphite-like at material surface.In addition, because the water vapour that oxy-compound dehydration forms in the PC/ABS engineering plastics can dilute oxygen and the concentration of inflammable gas in the atmosphere, help to make burning to interrupt.Moreover the thick material of oxygen acid of the phosphorus that the RDP decomposes produces can form the liquid film that one deck is covered in coke layer at material surface, and the ventilation property that it can reduce coke layer is not continued oxidation with protection, helps improving the flame retardant resistance of material.RDP reaches 15% when above, and engineering plastic materials can reach the fire-retardant rank of V-0.The RDP through using above-mentioned parts by weight and the PC and the ABS of above-mentioned parts by weight are used, and make that the flame retardant properties of PC/ABS engineering plastics is promoted greatly on the one hand, can not exert an influence to the PC/ABS mechanical performance of engineering plastic again on the other hand.
Particularly, the molecular weight of styrene-maleic anhydride copolymer (SMA) is between 120,000～150,000, and high-molecular weight SMA has excellent biological compatibility and amphiphilic, plays the effect of coupling system.The parts by weight of this styrene-maleic anhydride copolymer are 5～20 parts, are preferably 6～12.This styrene-maleic anhydride copolymer is an employed compatilizer in the PC/ABS engineering plastics.Because the solubility parameter difference of SMA and PC is very little; Good consistency is arranged each other; The slip that has reduced between PC and the ABS is flowed; And SMA can be at PC and ABS two alternate formation covalent linkage; Reactive force between PC and the ABS is strengthened greatly, make the PC/ABS mechanical performance of engineering plastic promote greatly; Simultaneously, SMA has very strong polarity, and PC/ABS engineering plastics polarity is increased, and has improved PC/ABS engineering plastics melt viscosity, and the melting index of PC/ABS engineering plastics is obviously descended, and realizes that the PC/ABS mechanical performance of engineering plastic further promotes.Further, the existence of a large amount of phenyl ring and the strong polarity of maleic anhydride make the PC/ABS engineering plastics have good heat-resistant among the SMA.Because SMA and RDP have high molecular, the resistance toheat of PC/ABS engineering plastics is influenced less, kept the high heat resistance of PC/ABS engineering plastics.
Particularly, this oxidation inhibitor is restriction not, is preferably primary antioxidant and auxiliary antioxidant mixture.The parts by weight of this oxidation inhibitor are 0.1～2 part.It is four [3-(3,5-di-t-butyl 4-hydroxy phenyl) propionic acid] pentaerythritol ester that described primary antioxidant is selected chemical name for use, trade(brand)name IRGANOX1010; Auxiliary antioxidant is selected three (2, the 4-di-tert-butyl-phenyl) phosphorous acid ester for use, trade(brand)name IRGANOX168, and Switzerland Ciba company produces, and compound proportion is IRGANOX1010/IRGANOX168=0.1/0.2.
Particularly, this ultraviolet absorbers is the benzotriazole category powder, for example, and one or more of UV234, UV944, UV327.The parts by weight of this ultraviolet absorbers are 0.1～2 part.
Further, these PC/ABS engineering plastics comprise that also parts by weight are other auxiliary agents of 0.1～3 part, and these other auxiliary agents are selected from one or more in static inhibitor, tinting material, lubricant or the releasing agent.This static inhibitor, tinting material, lubricant or releasing agent be restriction not, and part by weight each other is not restriction also.
See also Fig. 1, Fig. 1 shows the above-mentioned PC/ABS engineering plastics of embodiment of the invention preparation method, comprises the steps:
Step S01, supply raw materials:
Get the component of following parts by weight:
Step S02 prepares first mixture:
With the PC drying treatment, the PC after said ABS, solid-state Resorcinol-two (diphenyl phosphoester), styrene-maleic anhydride copolymer, oxidation inhibitor, ultraviolet absorbers and the drying treatment is mixed, obtain first mixture;
Step S03, extrude processing:
Said first mixture is extruded processing, obtain the PC/ABS engineering plastics.
Further, the component among the step S01 comprises that also parts by weight are other auxiliary agents of 0.1～3 part, and said other auxiliary agents are selected from one or more in static inhibitor, tinting material, lubricant or the releasing agent.
Particularly, among the embodiment of the invention PC/ABS engineering plastics preparation method, this PC, ABS, SMA, RDP, oxidation inhibitor, UV light absorber and other auxiliary agents with aforesaid identical, do not repeat to set forth at this.
Particularly, among the step S02, earlier with PC resin dry micro-moisture of surface adsorption of removing in 4～8 hours in 100 ℃ convection oven;
Then, the PC after above-mentioned ABS, solid-state Resorcinol-two (diphenyl phosphoester), styrene-maleic anhydride copolymer, oxidation inhibitor, ultraviolet absorbers and the drying treatment is added in the stirrer, mixes, obtain first mixture;
Particularly, among the step S03, this first mixture is extruded processing, obtain the PC/ABS engineering plastics.Not restriction of employed extrusion equipment in this step, for example, single screw extrusion machine and twin screw extruder.Extrude in the treating processes, parameter is:
200～220 ℃ in one district; 240～250 ℃ in two districts; 260～275 ℃ in three districts; 275～250 ℃ in four districts; Five districts: 270～250 ℃; 250～230 ℃ in six districts; 200～240 ℃ of heads; Screw speed is 250～300rpm.
Extrude postcooling, air-dry, particles that pelletizing promptly obtains environmental-friendly fire-retardant PC/ABS engineering plastics.
Embodiment of the invention PC/ABS engineering plastics preparation method, simple to operate, with low cost, generate high efficiency, be very suitable for suitability for industrialized production.
The embodiment of the invention further provides the application of above-mentioned PC/ABS engineering plastics in automobile, electronic product, electrical equipment, mechanical field.
Below in conjunction with specific embodiment above-mentioned PC/ABS engineering plastics and performance thereof are set forth in detail.
See also table one, table one is the PC/ABS engineering plastics component situation of embodiment one～six:
Table one
See also table two, table two is the PC/ABS engineering plastics The performance test results of above-mentioned table one embodiment one～six:
Table two
Can find out that from table two with the resultant increase of fire retardant RDP, the flame retardant properties of PC/ABS engineering plastics significantly improves.Because when containing the PC/ABS engineering plastics of RDP and being subjected to high temperature, RDP decomposes the oxygen acid that generates phosphorus, promotes the heat absorption of hydroxy-containing compounds to be dehydrated into the charcoal reaction and carries out, and generates the coke layer of graphite-like at material surface.In addition, because the water vapour that oxy-compound dehydration forms in the PC/ABS engineering plastics can dilute oxygen and the concentration of inflammable gas in the atmosphere, help to make burning to interrupt.Moreover the thick material of oxygen acid of the phosphorus that the RDP decomposes produces can form the liquid film that one deck is covered in coke layer at material surface, and the ventilation property that it can reduce coke layer is not continued oxidation with protection, helps improving the flame retardant resistance of material.RDP reaches 15% when above, and the PC/ABS engineering plastic materials can reach the fire-retardant rank of V-0.But with the increase of RDP consumption, its difficulties in dispersion in engineering plastics causes tensile property, and impact property descends obviously.
Secondly, comparative example's one, two, three, four prescriptions can find out that SMA constantly increases along with compatilizer, and melting index obviously descends in the system, the reduction of blend flow property.This is because the solubility parameter difference of SMA and PC is very little, and good consistency is arranged each other, and the slip that has reduced between PC and the ABS is flowed; And SMA can be at PC and ABS two alternate formation covalent linkage; The polarity of SMA increases system polarity, improved melt viscosity, thereby melting index descends obviously.As engineering plastics application project plastics; Requirement has than higher thermotolerance; Engineering plastic materials of the present invention has excellent thermotolerance; Mainly be because of the existence of a large amount of phenyl ring and the strong polarity of maleic anhydride among the SMA; Thereby the adding of SMA increases blend polarity makes consistency improve; And RDP is the polymer organic phosphorus flame retardant, because the molecular weight height to the heat-drawn wire influence of engineering plastic materials seldom, so material has excellent heat-drawn wire.
The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of within spirit of the present invention and principle, being done, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.
Claims (10)
1. PC/ABS engineering plastics comprise the component of following parts by weight:
2. PC/ABS engineering plastics as claimed in claim 1 is characterized in that, the parts by weight of said styrene-maleic anhydride copolymer are 6～12.
3. PC/ABS engineering plastics as claimed in claim 1 is characterized in that, the molecular weight of said styrene-maleic anhydride copolymer is 120,000～150,000.
4. PC/ABS engineering plastics as claimed in claim 1 is characterized in that, the parts by weight of said solid-state Resorcinol-two (diphenyl phosphoesters) are 10～20.
5. PC/ABS engineering plastics as claimed in claim 1 is characterized in that, comprise that also parts by weight are other auxiliary agents of 0.1～3 part, and said other auxiliary agents are selected from one or more in static inhibitor, tinting material, lubricant or the releasing agent.
6. like each described PC/ABS engineering plastics preparation method of claim 1～4, comprise the steps:
Get the component of following parts by weight:
With the PC drying treatment, the PC after said ABS, solid-state Resorcinol-two (diphenyl phosphoester), styrene-maleic anhydride copolymer, oxidation inhibitor, ultraviolet absorbers and the drying treatment is mixed, obtain first mixture;
Said first mixture is extruded processing, obtain the PC/ABS engineering plastics.
7. PC/ABS engineering plastics preparation method as claimed in claim 6 is characterized in that the parts by weight of said styrene-maleic anhydride copolymer are 6～12.
8. PC/ABS engineering plastics preparation method as claimed in claim 6 is characterized in that the parts by weight of said solid-state Resorcinol-two (diphenyl phosphoesters) are 10～20.
9. PC/ABS engineering plastics preparation method as claimed in claim 6 is characterized in that, the said treatment condition of extruding are:
200～220 ℃ in one district; 240～250 ℃ in two districts; 260～275 ℃ in three districts; 275～250 ℃ in four districts; Five districts: 270～250 ℃; 250～230 ℃ in six districts; 200～240 ℃ of heads; Screw speed is 250～300rpm.
10. like each described PC/ABS engineering plastics application in automobile, electronic product, electrical equipment, engineering goods of claim 1～5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011103304274A CN102344661A (en) | 2011-10-26 | 2011-10-26 | PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011103304274A CN102344661A (en) | 2011-10-26 | 2011-10-26 | PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102344661A true CN102344661A (en) | 2012-02-08 |
Family
ID=45543750
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011103304274A Pending CN102344661A (en) | 2011-10-26 | 2011-10-26 | PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102344661A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113136097A (en) * | 2021-05-12 | 2021-07-20 | 广东银禧科技股份有限公司 | Halogen-free flame-retardant antistatic natural-color PC/ABS alloy and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11269368A (en) * | 1998-01-28 | 1999-10-05 | General Electric Co <Ge> | Flame retardant polycarbonate resin/abs graft copolymer blend |
| CN101974216A (en) * | 2010-10-29 | 2011-02-16 | 大河宝利材料科技(苏州)有限公司 | Halogen-free flame-retardant PC/ABS alloy |
-
2011
- 2011-10-26 CN CN2011103304274A patent/CN102344661A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11269368A (en) * | 1998-01-28 | 1999-10-05 | General Electric Co <Ge> | Flame retardant polycarbonate resin/abs graft copolymer blend |
| CN101974216A (en) * | 2010-10-29 | 2011-02-16 | 大河宝利材料科技(苏州)有限公司 | Halogen-free flame-retardant PC/ABS alloy |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113136097A (en) * | 2021-05-12 | 2021-07-20 | 广东银禧科技股份有限公司 | Halogen-free flame-retardant antistatic natural-color PC/ABS alloy and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103524946B (en) | High-temperature-resistant thermoplastic polyvinyl chloride cable material and preparation method thereof | |
| CN101845197B (en) | High-performance halogen-free flame retardant ABS modified resin and preparation method thereof | |
| CN102746606B (en) | Hollow glass bead filling-modified acrylonitrile-butadiene-styrene (ABS) material and preparation method thereof | |
| CN101659779B (en) | Halogen-free flame-retardant ABS resin and preparation method thereof | |
| CN107286563B (en) | Intumescent flame retardant for ABS electrical switch outer cover and preparation and application thereof | |
| CN108102213B (en) | Flame-retardant polypropylene composition and preparation method and application thereof | |
| CN102746607B (en) | Insulated and heat conducting environment-friendly flame-retardant ABS (Acrylonitrile Butadiene Styrene) resin and preparation method thereof | |
| CN101942186B (en) | Halogen-free flame-retardant polycarbonate material and preparation method thereof | |
| CN104231575B (en) | Halogen-free and phosphorus-free PBT enhanced composite material and preparation method thereof | |
| CN106009585A (en) | Halogen-free flame retardation polycarbonate material and preparation method thereof | |
| CN102516732A (en) | Polycarbonate (PC) resin/acrylonitrile-butadiene-styrene (ABS) alloy and preparation method thereof | |
| CN102532826A (en) | Low-cost flame-retardant fiberglass-reinforced PBT (Polybutylene Terephthalate) engineering plastic and preparation method thereof | |
| CN106905674B (en) | A kind of Flame-retardant PET and PC composite material and preparation method | |
| CN102702612B (en) | High-flow precipitation-resistant halogen-free flame-retardant polypropylene composite material and preparation method thereof | |
| CN102775754A (en) | Halogen-free composite flame retardant poly carbonates (PC)/acrylonitrile butadiene styrene copolymers (ABS) alloy and preparation method thereof | |
| CN103044848B (en) | ABS/PMMA matrix material and preparation method thereof | |
| CN104725797B (en) | Method for preparing flame-retardant plastic composite material | |
| CN105885338A (en) | ABS flame-retardant masterbatch for industrial helmet and preparation method of ABS flame-retardant masterbatch | |
| CN112029189A (en) | Halogen-free flame-retardant polypropylene composite material and preparation method thereof | |
| CN104448830A (en) | Phosphorus-silicon composite flame retardant as well as preparation method and application thereof | |
| CN101624457A (en) | Environmental protection based red mud combination modification synergism fire-retardant polyethylene | |
| CN102382439A (en) | Modified polycarbonate and preparation method thereof | |
| CN104419166A (en) | PC flame retardant master batch | |
| CN103360739A (en) | Phosphorus-based synergetic and flame-retardant PC (Polycarbonate)/ABS (Acrylonitrile Butadiene Styrene) alloy material and preparation method thereof | |
| CN102344661A (en) | PC (Polycarbonate)/ABC (Acrylonitrile-Butadiene-Styrene copolymer) engineering plastics, as well as preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20120208 |