WO2012159242A1

WO2012159242A1 - Bias piece with high coercivity, manufacturing method and acousto-magnetic anti-theft marker made thereof

Info

Publication number: WO2012159242A1
Application number: PCT/CN2011/074379
Authority: WO
Inventors: 李霖
Original assignee: 宁波讯强电子科技有限公司
Priority date: 2011-05-20
Filing date: 2011-05-20
Publication date: 2012-11-29

Abstract

A bias piece with high coercivity which can be stably manufactured, a manufacturing method and an acousto-magnetic anti-theft marker made thereof are provided. The bias piece is made as an alloy strip containing 10-14% by weight of Mn, the total amount by weight of not more than 7% of one or more transition metals and the balance being Fe. The alloy strip is cold-rolled to a final thickness and subjected to a final aging process for more than 5 minutes at a temperature lower than 590℃ then the bias piece can be manufactured. The thickness of the bias piece is 0.065 - 0.18mm and its direct current coercivity is 56-90 Oe. The manufacturing method of the bias piece includes the following steps: cold rolling the alloy strip to 0.07-0.15mm, subjecting same to an aging process at a temperature of 450-570℃ for 0.5 - 20 hours to obtain a magnetic strip having a coercivity of 60-85 Oe, cutting the magnetic strip into the required dimensions. The present invention overcomes the prejudice that the bias piece for an acousto-magnetic marker having high coercivity must contain cobalt or nickel, and proves that high coercivity can be obtained through use of an inexpensive Fe-(10-14wt%) Mn-based alloy processed by the present method.

Description

High coercivity biasing sheet, manufacturing method thereof and acoustic magnetic anti-theft label made thereof

The invention relates to a commercial anti-theft protection alarm device and a manufacturing method thereof, in particular to a cobalt-free nickel-free or low-nickel high-coercivity biasing sheet which can be stably produced, a manufacturing method thereof and a sound made therefrom Magnetic anti-theft tag.

Background technique

Acoustic magnetic technology has been widely used in electronic object surveillance anti-theft devices for more than 20 years. U.S. Patent No. 4,510,489, which discloses the original invention, discloses that certain amorphous alloy material ribbons can emit strong resonance due to their high magnetic-elastic coupling coefficient. Signals, and using this principle to successfully apply these materials to commercial anti-theft systems (acoustic magnetic systems), such as anti-theft systems in large supermarkets. Acoustic magnetic systems mainly include detectors, decoders and verifiers, anti-theft acoustic magnetic targets, etc. The commercially widely used detectors are Ultramax detectors manufactured by Sensormatic Electronics Corporation of the United States. The detector is capable of transmitting a 58 kHz pulse wave that is used to excite an undecoded (active) anti-theft acoustic magnetic target in the detection zone to resonate at 58 kHz to produce a strong signal that is detected by the detector coil within the detector. Accept, trigger the alarm by the signal amplification analysis. Decoding is to demagnetize the biasing piece in the anti-theft acoustic magnetic target to shift the resonant frequency out of the detection band window, while also significantly reducing the resonance signal strength without triggering an alarm. Anti-theft acoustic magnetic targets can be divided into two types: anti-theft acoustic magnetic hard targets and anti-theft acoustic magnetic labels (hereinafter referred to as acoustic magnetic labels). The anti-theft acoustic magnetic hard target uses an amorphous ribbon as a resonant piece, and a permanent magnet material (such as a permanent magnet bonded ferrite) is used as the offset piece. Such a theft prevention target (for example, Supertag I, II, III produced by Sensormatic) cannot Decoding, can only be reused in the store, the anti-theft hard target on the paid item is removed by opening the mechanical needle lock device with the unlocker The target method allows the item to leave the store without triggering the door alarm. The acousto-magnetic label also uses an amorphous ribbon as the resonator, but uses a "semi-hard magnetic" material as the biasing element (for example, the DR acoustic magnetic anti-theft soft label manufactured by Sensormatic). Such acoustic magnetic labels can be repeatedly decoded and activated. The acousto-magnetic label on the paid item causes the item to leave the store without deactivating the door alarm by means of demagnetization decoding on the decoder. The biasing piece is a key component in the acoustic magnetic tag. Determining the resonant frequency of the acoustic magnetic tag enables the detection system to clearly distinguish the active and inactive states (decoded state) of the acoustic magnetic tag, and greatly affects the anti-theft tag. Performance and price. Therefore, international research and development of offset sheet materials has been carried out. After the US patent US4510489, there are some new patents relating to the composition and processing methods of offset sheet materials, such as US Patent No. 4,536,229, US5351033, US5716460, US5729200, US6001194, US6181245, US6689490, US6893511 and the like.

The "semi-hard magnetic" material has a DC coercive force between soft magnetic material and hard magnetic material, which is 10-300 0e. When the coercive force of the acousto-magnetic biasing sheet is high (for example, 56-90 0e), the acoustic magnetic label produced by using such a material as the offset sheet is more resistant to environmental interference magnetic fields during transportation, storage and use. high. However, such materials are generally costly due to the presence of cobalt (strategic matter) or nickel (which has become increasingly expensive and volatile in recent years). For example, FeCrCo semi-hard magnetic biasing elements, which have been used commercially for a long time, contain expensive cobalt (about 7-17 wt%). Later, Germany's Vacuumshemelze (VAC) developed a semi-coercive force of approximately 70-80 Oe for SemiVac90 (FeCrCoNiMo, see VAC product specification, and US Patent No. 5729200, US6181245). Cobalt content but still can not completely get rid of cobalt and nickel. Further, the offset sheet material developed by Carpenter Technology Corporation (CarTech) of the United States has a low coercive force of about 20 Oe of MagneDur 20_4 (Fe_20Ni-4Mo, see US Pat. No. 5,729,200, US Pat. No. 6,811,245). It still contains a relatively high content (greater than 8 wt%) of Ni. Close to the same period, the German Vacuumshemelze company again The offset film Sensorvac (FeNiAlTi, see VAC, US Pat. No. 6,689,490), which reduces the coercivity to around 20 0e, does not contain cobalt, but still contains higher nickel (8-25% by weight).

In fact, as early as 1980, Dr. S. Jin of Bell Labs in the United States conducted a laboratory investigation on Fe-Ni and Fe_Mn alloys ("High-Remanence Square-Loop Fe-Ni AND Fe-Mn Magnetic Alloys" , IEEE Transactions On Magnetics Vol. Mag-16 No. 5 Sept 1980), indicating the use of Fe - (8-16wt%) Mn alloy wire (not strip) after cold stretching (deformation greater than 80%) + 500-550 ° C aging 3. 5 hours cold stretching (deformation greater than 95%) +450 °C aging 10 minutes to 2 hours, you can get Hc = 28 Oe / Br = 18000 Gs, Hc = 85 Oe / Br = 15000 Gs, Hc = A combination of performance of 240 Oe/10000 Gs. This magnetic property (either Br qualified but He is too low, or He is qualified but Br is too low) and this specially processed Fe-Mn wire has been in use for a long time since 1980, and no actual application can be found. Reports on technology products (especially the acoustic and magnetic anti-theft labels that were born in 1982). It is worth mentioning that the processing method of wire and strip (especially the difficulty of processing technology of filament and ribbon) is completely different.

In 1996, the American company Arnold disclosed a US patent US5716460: using F-(8 -18wt%) Mn alloy (actually only one component Fe-12. 9wt% Mn-0. 01wt%Cr) has been taught by Dr. Jin. In that case, the cold rolling deformation is at least 40%, then aging at 400 °C for at least 30 minutes, and then cold rolling at least 75%. The last step is the indispensable key technical feature of the invention, that is, the final strip after cold rolling. Short-time annealing with a time of less than 3 minutes when the heat treatment temperature is greater than 525 ° C (actually 525 - 625 ° C). Want to obtain a material with a coercivity of at least 20 0e, Br of at least 8000 Gs. Although there have been suggestions in its specification, the embodiment of the Arnold method (US5716460) and all of the claims do not suggest the use of such materials for the recording of acoustic and magnetic anti-theft labels, and therefore whether the material is truly acceptable ( The acoustic distance of the alarm distance and the decoding performance are all acceptable.) The acoustic magnetic label is undefined. Another disadvantage of the Arnold method (US5716460) is that it is an indispensable essential key feature for the final annealing of 525 ° C (very low temperature) / less than 3 minutes (very short time) of annealing, which is in the actual process technology It is a very unstable manufacturing method. In fact, the limited data listed in Table 1.1 of the Arnold method (US5716460) has shown that as long as the fluctuation of temperature in about 1 minute or 100 °C, it is possible to produce about 20% coercivity He and remanence Br Numerical changes. This is obviously not practical for the extremely high raw material performance consistency requirements of the acoustic resonance frequency window with a very narrow alarm resonance frequency window (57. 8-58. 2 kHz).

Both Dr. Jin and the Arnold method (US5716460) use the necessary technical steps for intermediate aging in the γ (austenitic) and alpha (ferritic) two-phase regions for more than 30 minutes (preferably several hours) after cold deformation. This is also disadvantageous for large production. Since the two-phase zone aging temperature is 400-600 ° C (which is lower than the lower temperature), the hydrogen protection effect is not obvious, and the cold-rolled strip after refining is easily oxidized again. In addition, the steel strip is already thinner, and the loss of the surface of the cold rolled strip is greatly increased, and the processing cost is increased, which offsets the price advantage of cobalt-free nickel-free or low-nickel.

The method of the method of the Arnold method (US5716460) (the same as the other method of the strip film processing), including the first roll mill (to 0. 2 mm), and then the multi-roll mill to finish rolling to about 0. 05mm ( That is, the rolling method of the offset sheet thickness which is generally accepted in the industry. A person skilled in the art knows that a 4-roll mill with a lower processing cost can be rolled up to about 0.07. Technical requirements 0. 065mm thickness or less has to use Z-mi ll (20-roll or 26-high-precision rolling mill). The processing cost is abruptly much higher than the material cost of the base metal (such as Fe-Mn based alloy) strip. This is inconsistent with the economic goal of reducing the cost of a large-scale offset sheet without cobalt or nickel or low nickel, and is not necessary.

In addition, since the US 5,729,200 invention has claimed to reduce the coercive force of the offset sheet to 20 Oe, the development of semi-hard magnetic bias materials for acoustic magnetic labels has been biasedly positioned in the low coercivity range for more than a decade. However, in fact, the US 5729200 invention originally conceived that the effect of reducing the peak of the demagnetizing field (to 35 0e) is not practical. Commercially, the decoder that is normally used still reaches the peak of the demagnetizing field by several hundred 0e to ensure the complexity at the checkout counter. In high-speed environments, the tag can be reliably demagnetized in all directions without false alarms. At the same time, in the "source labeling plan", the label is placed on the commodity in the place where the commodity is produced (such as Asian countries). After many times of sea transportation, land transportation, and reaching the shopping mall (such as in Europe or America), it needs to remain stable. The biased piece magnetization state (and the optimal activation state of the tag). However, the storage and transportation environment is very complicated, including the experience of the iron-based material shelf or transfer roller, the residual magnetic field of the drum, the leakage magnetic field that the label is put together, the security equipment, various electrical equipment and the stray magnetic field of the low-frequency power supply. Therefore, acoustic magnetic labels made with offset sheets with low coercive force (Hc=20-25 0e) are not without difficulty to maintain stability. For example, individual label suppliers require that the majority of merchants in their label specifications not to The acoustic magnetic anti-theft tags produced by them are briefly exposed to environmental magnetic fields greater than 8 Gauss (0e), and it is almost impossible for different merchants to know exactly where the magnetic magnetic labels are stored, transported, and in various areas of the mall. The peak of the environmental magnetic field is not so weak magnetic field 8 Gauss. The merchant has no responsibility and no way to control all the environmental magnetic field strength. Therefore, the strict limitation of such conditions of use is only a unilateral exemption clause. For label suppliers, this is not a positive and fundamental way to address such label stability issues and cost issues.

Currently used Hc = 20 0e FeNiTiAl or FeNiMo low coercivity semi-hard magnetic offset strips require extremely tight control of aging temperature/time after cold rolling. Because the aging process of this type of alloy is a process of increasing the coercivity from low to high, the low coercive force is the early state in which the aging of the aging is rapidly rising, and it is extremely sensitive to the aging temperature, and it is missed when you are not careful. The middle He is about 20 0e of the target process window, which makes He rise too high and scraps the thin steel strip. Therefore, the requirements for production equipment are extremely high. The alloy with high coercivity (56_90 0e ) Fe_12wt% Mn has a wide heat treatment temperature range because He is The sensitivities of the aging temperature are relatively gentle in the high He range of the latter part of the aging, and it is easy to manufacture high-quality offset strips with high consistency in large-scale common production equipment environment, which greatly reduces the strictness of production equipment and processes. Sexual requirements reduce the cost of the offset sheet.

Another practical problem that is closely related to the stability of acoustic magnetic labels is that the inventors and suppliers of the current low coercivity _{Hc = 20 0e} label have realized that the current acoustic magnetic field made of low coercivity biasing sheets When the label is stored and transported, the sum of the leakage magnetic fields when the thousands of labels are close to each other is greater than 10 0e, which causes the labels to demagnetize each other and the alarm performance is deteriorated. Therefore, in order to avoid the instability of the label, the inventors and suppliers of the low-coercivity label have to adopt a complicated alternating magnetization method, so that the label magnetization direction is strictly controlled, and the south pole and the north pole alternately activate the charge. For details, see the description of the specification in the low coercivity labeling patent (US Pat. No. 5,729,200) and the detailed description of the apparatus and method in its subsequent patent, U.S. Patent No. 6,020,017. This makes the manufacture, storage and transportation of low coercivity labels costly and complicated. With high coercivity labels, a large number of labels (such as thousands, tens of thousands) that are magnetized in the same direction (or after thousands of magnetization methods) are discharged together and cannot cause the labels to demagnetize each other, so they are manufactured. It is simple and reliable to store and transport acoustic labels.

An example of the structure of an existing acoustic magnetic tag (see U.S. Patent No. 6,359,563), as shown in Fig. 3A of the patent, includes an elongated plastic case and a lid attached thereto, the cover being sequentially from top to bottom The cover film, the double-sided tape, the offset piece of the semi-hard magnetic material and the cover film are superposed, and one or more pieces of the superimposed resonator piece whose size is matched with the case body are placed in the cavity of the box body, wherein the offset piece In the case of parallelograms or chamfered parallelograms, the shape of the offset sheet that was later developed may also be rectangular.

In summary, there is an urgent need in the market for a method for manufacturing a high coercivity biasing sheet which is cobalt-free, nickel-free or low-nickel (less than 8 wt% Ni) and which can be stably produced, and acoustic magnetic anti-theft using the biasing sheet. Labels address the growing demand for this product. Summary of the invention

In order to solve the above technical problems, the present invention provides an offset sheet which is cobalt-free, nickel-free or low-nickel, low in cost, and high in coercive force.

The present invention also provides a method for large-scale stable manufacturing of the above high coercivity biasing sheet. The present invention also provides a decodable acoustic magnetic anti-theft tag comprising the above biasing sheet.

The invention also provides a magneto-optical label label arrangement combination and a combined magnetization activation method for a large number of the above-mentioned offset sheets, so that the total leakage magnetic field of the label is insufficient when the label is formed into a label or a label Self-demagnetization due to mutual influence. It greatly simplifies the process of label activation, storage and transportation while increasing reliability.

The above technical problems of the present invention are mainly solved by the following technical solutions:

A high coercivity biasing sheet, which is cold rolled to a final thickness by 10 to 14 wt% of Mn, a total of no more than 7 wt% of any other transition metal or balance of Fe, to a final thickness. After a final aging treatment of more than 5 minutes and less than 590 ° C, the thickness is 0. 065-0. 18 mm, and the DC coercive force is 56-90 Oe. In comparison, the bias sheet of the present invention having a high coercive force (e.g., 56_90 Oe ) based on an inexpensive metal Fe-Mn has a significantly improved offset sheet than a low coercive force (Hc = 20 Oe ). Reliably resisting the ability of the magnetic field to demagnetize, the corresponding acoustic magnetic label is more stable, and it has been experimentally proven that it can be completely demagnetized and deactivated on the currently widely used decoders. In other words, if there is no cobalt, no nickel or low nickel, and it is easy to manufacture and low in cost, and can be reliably demagnetized in the decoder currently used, the bias magnet pair with higher coercive force (56-90 Oe) is used to improve the acoustic magnetic field. The stability of label storage, transportation and use is economically and technically advantageous. (It can completely replace the low-coercivity semi-hard magnetic material with a high nickel content of about 20 Oe for He).

Preferably, the sum of any one or more of the transition metal in the alloy ribbon does not exceed 5% by weight. 5重量百分比。 The Mn content of the alloy ribbon is 11. 5_12. 5wt%, the sum of any other transition metal or more does not exceed 2wt%, the balance is Fe.

The tempering treatment temperature is 450-570 ° C, the time is 0. 5 hours - 20 hours after the coercive force is obtained. =60_85 Oe magnetic strip, which is cut into the size of the desired offset sheet to obtain a high coercivity biasing sheet; the alloy ribbon contains 10-14 wt% Mn, and the total does not exceed 7 wt% Or a plurality of transition metal metals, the balance being Fe.

Preferably, the strip is slit to a width of 4 to 10 inches and then cut to a length of 32 to 40 to obtain an offset sheet. A method for manufacturing a high coercivity biasing sheet, which comprises using an alloy material of any one or more transition metals and a balance of Fe having a composition of 10 to 14 wt% Mn and a total of not more than 5 wt%, after smelting, ingot casting, Hot-rolled, hot-rolled, hot-rolled oxidized surface, softened at 840 ° C, with a 4-roll mill (without Z-mi ll, such as a 20-roll or 26-high-precision mill) cold rolled to 0. 07-0. 09 After 匪, do a long time aging treatment at 540 °C for 2-10 hours.

Preferably, the alloy material is subjected to cold rolling only after cold rolling +490 ° C / 5 hours final thickness aging, without performing any intermediate thickness at a lower temperature of 400-600 ° C _{Y -} α dual phase zone aging deal with.

01- The thickness of the alloy is 0.15_12. 5wt% Mn, the total of the other or more than 2% of the transition metal, the balance of the Fe thin alloy strip, the thickness of 0. 07- 0. 085 mm.

An acousto-magnetic anti-theft tag comprising an elongated box body and a magnetic offset piece, the acousto-magnetic anti-theft tag comprising a high coercivity biasing piece as described above, and at least one piece having a length of 35-45 inches and a width of 5至之间。 The resonant frequency of the active state of the tag is 57. 1-58. 9 kHz. 5 kHz。 Further, the active state resonant frequency is 57. 5-58. 5 kHz.

An acoustic magnetic anti-theft tag comprising a long and narrow box body and a magnetic offset piece, wherein a cavity of the box body is provided a diaphragm, the cover is covered with a cover made of a double-sided tape and a cover film, and the cover film, the magnetic offset piece and the resonance piece are arranged in a layer, and the magnetic offset piece is as described above. High coercivity material offset sheet.

The arrangement structure of the acoustic magnetic anti-theft tag, wherein the acoustic magnetic anti-theft tag is closely arranged on the same plane as a single version, and at least one edge of the acoustic magnetic anti-theft tag is spaced apart from the edge of the adjacent acoustic anti-theft tag by less than 0 1 mm, consisting of 40-120 labels in a single version, each box is commercially available with at least 20 labels, and the ratio of labels with the same bias sheet magnetization direction in each version is 50%-100%.

Another arrangement structure of the acoustic magnetic anti-theft tag, wherein the acoustic magnetic anti-theft tags are parallel to each other and form a label perpendicular to the length direction of the supporting bottom band, and the edge of the acoustic magnetic anti-theft tag and the adjacent acoustic magnetic anti-theft The label edge spacing is 2-4 mm, and the 2000-8000 labels are composed of a single volume. Each box is commercially available with at least one label, and the ratio of the label with the same biasing sheet magnetization direction in each volume is 50%-100%.

Therefore, the present invention has the following features compared to the prior art:

1. The present invention overcomes the technical bias of cobalt or nickel in the high coercivity of the acousto-magnetic label offset sheet, demonstrating that only a very inexpensive Fe-(10-14 wt%) Mn-based alloy has been subjected to the steps disclosed by the present invention. High coercivity can be obtained.

2. The method for manufacturing the offset sheet of the present invention eliminates the technical disadvantage of high processing cost of rolling with Z-mi ll (20-roll or 26-roll multi-roll high-precision rolling mill), saving expensive final processing costs and maintaining Low price advantage of Fe-Mn based alloy bias materials.

3. The method of the offset sheet of the invention eliminates the step of intermediate aging treatment which is considered necessary in the past, saves processing cost and material cost, and has simple process and convenient processing.

4. The method of the biasing sheet of the invention eliminates the technical prejudice that the heat treatment of the final thickness of the Fe-(8-18wt%) Mn material can not exceed 3 minutes, and prolongs the aging heat treatment time to 1-10 hours of the process window. The offset strips with consistent coercivity in mass production are made simple and controllable. 5. The acousto-magnetic anti-theft tag of the present invention is manufactured by using a high coercivity low-cost Fe_(10-14wt%) Mn-based alloy material, which greatly improves the label stability and has obvious cost advantages, and at the same time, breaks He of about 60 0e. The biasing material is not susceptible to technical bias in commercial deactivator demagnetization. The label of the invention has strong market competitiveness and vitality.

6. The acoustic magnetic anti-theft tag of the present invention is manufactured by using a high coercivity low-cost Fe_(10-14wt%) Mn-based alloy material, which greatly improves the label stability and has obvious cost advantages, so that the magnetization activation method must be eliminated. Technical bias for alternating magnetization directional limitations. It makes the label activating, storing and transporting the label simple and reliable.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of a label of the present invention.

DESCRIPTION OF REFERENCE NUMERALS 1 magnetic offset sheet, 2 resonator sheet, 3 box body, 4 cover film, 5 lids, 7 double-sided tape. Specific form

The technical solutions of the present invention will be further specifically described below by way of embodiments and with reference to the accompanying drawings. The techniques used in the following examples, unless otherwise stated, are conventional techniques known to those skilled in the art; the instrumentation used, unless specifically stated in the specification, is available to those skilled in the art Obtained by public means.

Example 1:

The alloy material (containing 12. lwt% Mn, 0.05% by weight Cr, balance Fe) is smelted and then ingot, hot forged, smelted and ingot, hot forged, hot rolled to 5 匪, the surface oxide layer is removed, and then the surface oxide layer is removed. Cold rolling to 0. 5 匪, 850 °C Single-phase zone rapid softening treatment to prevent excessive oxidation, then directly cold-rolled to 0. 08 用 in a 4-roll mill, placed in a vacuum furnace at 490 ° C / 6 hours in the dual phase zone After aging, slitting into different coils of 6 mm width, and then cutting the coil into a 38 mm long offset sheet by a high speed shear, the typical magnetic properties of the Fe-Mn based alloy biasing sheet See Table 1.

Example 2:

The alloy material (containing 12.8 wt% Mn, 1. lwt% Ni, 0.05 wt% Cr, balance Fe) is smelted and then ingot, hot forged, smelted and ingot, hot forged, hot rolled to 5 匪, 5小时双相。 The surface is then cold-rolled to 0. 5 匪, 850 °C single-phase zone softening treatment, and then directly cold-rolled to 0. 115 mm with a 4-roll mill, placed in a vacuum furnace 540 °C / 2. 5 hours duplex After the aging period, the slits were cut into different coils of 6 mm width, and the coils were cut into 36 mm long offset sheets by a high speed shear. The magnetic properties were then tested. The typical magnetic properties of the Fe-Mn based alloy biasing sheet are shown in Table 1.

Example 3:

The alloy material (containing 10. 5 wt% Mn, 1. lwt% Mo, 0.05 wt% Cr, 0.3 wt% Ti, balance Fe) is smelted and then ingot, hot forged, smelted, ingot, hot forged, The hot-rolled to 5 匪, the surface is then cold-rolled to 0. 5mm, 850 ° C single-phase zone softening treatment, and then directly cold rolled to 0. 08 mm with a 4-roll mill, placed in a vacuum furnace 570 ° C / 1 After the aging of the two-phase phase, the magnetic properties were tested. The typical magnetic properties of the Fe-Mn based alloy biasing sheet are shown in Table 1.

The acoustic magnetic anti-theft tag manufactured by using the above-mentioned offset piece comprises a long and narrow box body 3 and a magnetic biasing piece 1. The cavity of the box body 3 is provided with a resonance piece 2, and the box body is covered with a double-sided tape and a cover. The cover 5 composed of the film 4, the cover film 4, the magnetic offset piece 1 and the three pieces of the resonance piece are arranged in layers, as shown in Fig. 1, the resonance piece is a FeNiMoB amorphous resonance element having a width of 6 mm. See Table 2 for the comparison between the alarm performance of the anti-theft tag and the DR tag made of the low coercivity offset piece.

The existing Hc=20_25 Oe semi-hard magnetic material is used as the offset sheet to form the DR acoustic magnetic label and the high coercive force (56-90 Oe ) material of the embodiment 1 is used as the offset sheet for the acoustic magnetic label decoding (demagnetization). The effect comparison data is shown in Table 3. 1 Typical Magnetic Properties of Fe-Mn Based Alloy Bias Sheets Obtained in Examples 1-3 Examples Aging Temperature Aging Time He Br Bm 氺Br/Bm

( °C ) (hours) (Oe ) (Gs ) (Gs )

1 490 6 63 11200 12800 88%

2 540 2. 5 68 7300 9200 80%

3 570 1 89 3900 6000 65%

Note: Bm is the magnetic field strength at the maximum magnetic field strength of 150 Oe used in the test.

Table 2 Example of High Coercivity Fe-Mn Based Alloy Bias Sheet 1 Comparison of the alarm performance of the acoustic magnetic anti-theft tag with the DR tag made of the low coercivity offset piece

Acoustic magnetic tag detector can

The farthest distance detected (cm)

;Example 1 label 82 DR label

83 Wang:

1. DR sound magnetic label: American sensormatic company originating Hc=20_25 Oe offset sheet + FeNiCoSiB resonator sheet magnetic anti-theft label

2. The detector is a single-chassis Ultropost commercial detector manufactured by Sensormatic, which is widely used. The detection is performed perpendicular to the surface of the acoustic magnetic label detector in the direction of the acoustic magnetic label, and then the two alarm distances are measured in the direction of the inverted magnetic magnetic label.

It can be seen from the data in Table 2 that the label of the present invention can be similarly commercialized compared with the existing DR label. The detector reliably detects the alarm. This is an important basis for the label of the present invention to be used normally in the market. Table 3 Acoustic magnetic tag decoding of the existing Hc=20-25 Oe semi-hard magnetic material as a biasing piece DR magnetic magnetic tag and the high coercive force (56-90 Oe) material of the present invention as an offset piece (demagnetization deactivation) effect comparison

Note:

1. Remove the label from far and near to a preset distance and remove it to detect deactivation performance.

2. Decoder 1: Sensormatic Slimpad decoder, the label length is parallel to the decoder surface.

Decoder 2: Sensormatic RapidPad decoder, label length perpendicular to the decoder surface

3. Acoustic magnetic label demagnetization tester: Sensor checker's double checker

As can be seen from the data in Table 3, the tag of the present invention can be demagnetized by the same commercial decoder as compared with the current DR tag. This is an important basis for the invention label to be used in the market.

High magnetic force Acoustic magnetic standard of Fe-Mn based alloy offset sheet ^: Mechanical failure stability test:

The label made in the first embodiment is bent along the length center line toward the resonator side to 90 degrees, so that the offset sheet is Fully 90 degree bending plastic deformation, and then pressing the center line of the label length direction, the label is pulled back to the original straight shape, and the offset piece is plastically deformed again so that the label is substantially reset in the length direction. Test the change in resonant frequency before and after the label is bent. Table 4 lists the measured values of the resonant frequency change.

Table 4 High coercivity test of the acoustic magnetic label of the present invention for resisting mechanical damage

It can be seen from the data in Table 4 that the resonant frequency change value of at least one of the labels of the present invention after the above bending method is less than 0.995 kHz, so the label of the present invention is highly resistant to mechanical bending damage. The alarm frequency window is 57. 7-58. 3 kHz commercial alarm device, the above-mentioned extreme mechanical damage has a very limited effect on the resonant frequency, and the alarm performance is not very good after encountering intentional or unintentional bending. Great impact.

The acoustic magnetic label of the high-force Fe-n-based alloy biasing sheet resists the demagnetizing field stability test produced by the combination of a large number of labels: 25000 labels made by the offset sheet of the embodiment 1 are all pressed one by one. The direction is activated, and the North Pole mark is marked on each label, and then all the tests are performed according to the methods listed in Table 2, and the qualified labels with the two-way alarm distance of 75 cm or more are selected for the following experiment.

Arrangement 1 :

The layout of the labels: 4X12=48 labels per edition, and 5040 of the above experimental labels per 105 editions. All labels in the north pole are oriented in the same direction. Open the box after loading the box, and simulate the customer to take it off when actually using it. For each label, the alarm performance tests listed in Table 2 are performed one by one. The experimental result is that the 5040-packed labels have a two-way alarm distance of 75 cm or more, all of which are qualified. It is proved that the combination mode does not demagnetize each other in the case where the possible leakage magnetic field is maximum, and is stable, so that it is not necessary to impose any limitation on the magnetization direction.

Arrangement 2 :

Label arrangement: 5000 test labels per roll, inner diameter 75 mm. The PET separation bottom width is 48mm, and the label is perpendicular to the length of the PET separation base strip. Each label is spaced 3 mm apart. A total of 3 rolls were assembled and loaded into the carton. The 3-volume trays are stacked neatly. All labels in the north pole are oriented in the same direction. Then, when simulating the actual use of the customer, remove each label of the volume sandwiched in the middle, and perform the alarm performance tests listed in Table 2 one by one. The experimental result is that the 5,000-packed label has a two-way alarm distance of 75 cm or more, all qualified. It is proved that the combination mode does not demagnetize each other in the case where the possible leakage magnetic field is maximum, and is stable, so that it is not necessary to impose any limitation on the magnetization direction. It is to be understood that the examples are merely illustrative of the invention and are not intended to limit the scope of the invention. The acoustic magnetic anti-theft tag of various structures can be manufactured by using the offset piece provided by the present invention, and the present invention only illustrates the application of the offset piece of the present invention by the above-mentioned Embodiment 1. In addition, it is to be understood that various modifications and changes may be made by those skilled in the art in the form of the present invention.

Claims

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A high coercivity biasing sheet, characterized in that: the biasing sheet is cooled by 10 to 14 wt% of Mn, a sum of no more than 7 wt% of any other transition metal or a balance of Fe 065-0. 18 mm, DC coercive force is 56-90 0e. After the final thickness is rolled to a final aging treatment of more than 5 minutes and less than 590 ° C, the thickness is 0. 065-0. 18 mm, DC coercive force is 56-90 0e

2. The high coercivity biasing sheet according to claim 1, wherein: the sum of any other transition metal or alloys in the alloy ribbon does not exceed 5% by weight

The Mn content of the alloy ribbon is 11. 5-12. 5wt%, the sum of any one or more transition metals is not more than 2wt%. , the balance is Fe

The aging treatment temperature is 450_570 ° C, the time is 0. 5 hours - 20 hours later, the method is as follows: Magnetic strip of coercivity = 60-85 Oe, which is cut into the size of the desired offset sheet to obtain a high coercivity biasing sheet; the alloy ribbon contains 10-14 wt% Fe, and the total does not exceed 7 wt% Any other or more transition metals, the balance is Fe

The manufacturing method according to claim 4, wherein the strip is slit to a width of 4 to 10 mm, and then cut into a length of 32 to 40 mm to obtain an offset sheet.

A method for producing a high coercivity biasing sheet, characterized by: using an alloy material of any one or more transition metals and a balance of Fe having a composition of 10-14 wt% Mn total and not more than 5 wt% After smelting, ingot casting, hot forging, hot rolling, removing the hot-rolled oxidized surface, softening treatment at 840 ° C, cold rolling with a 4-roll mill to 0. 07-0. 09, at less than 540 ° C 2-10 hours of long-term aging treatment.

7. The manufacturing method according to claim 6, wherein: the alloy material is subjected to rapid softening treatment only after high-temperature single-phase region (higher than 840 ° C) after hot rolling + cold rolling + 490 ° C / 5 hours Final thickness aging, The aging treatment of any intermediate thickness of the 400-600 ° C _Y -α dual phase region at a lower temperature is not performed.

The manufacturing method according to claim 6 or claim 7, wherein: the alloy material is 11. 5-12. 5wt% Mn, and the total of no more than 2wt% of any other transition metal or groups, 085毫米。 The thickness of the alloy is 0. 07-0. 085 mm.

9. An acousto-magnetic anti-theft tag comprising an elongated box, a magnetically biased sheet, characterized in that: the acousto-magnetic anti-theft tag comprises the high coercivity biasing sheet of claim 1 and at least one piece of length 35至之间。 The resonant frequency of the active state of the tag is 57. 1-58. 9 kHz.

The oscillating magnetic resonance code of the active state is 57. 5-58. 5 kHz o

An acoustic magnetic anti-theft tag, comprising a long and narrow box body and a magnetic offset piece, wherein a cavity is provided in the cavity of the box body, and the box body is covered with a cover made up of a double-sided tape and a cover film, The cover film, the magnetic biasing piece and the resonant piece are arranged in a layered manner, and the magnetic biasing piece is the high-coercive force material biasing piece according to claim 1.

12. The arrangement structure of an acoustic magnetic anti-theft tag according to claim 9 or 11, wherein: the acoustic magnetic anti-theft tag is closely arranged on a same plane as a single plate, and the edge of the acousto-magnetic anti-theft tag has at least one edge The distance between the edge of the adjacent sound and magnetic anti-theft label is less than 0.1 mm, and the composition of 40-120 labels is a single version. The label of each commercially available label is at least 20 versions, and the proportion of the label with the same biasing piece magnetization direction in each version. 50% - 100%.

13. The arrangement structure of an acoustic magnetic anti-theft tag according to claim 9 or 11, wherein: the acoustic magnetic anti-theft tags are parallel to each other and form a label perpendicular to a length direction of the support baseband, and the sound magnetic anti-theft is The edge of the label is spaced from the edge of the adjacent acoustic magnetic anti-theft label by 2-4 mm, and the 2000-8000 label is composed of a single roll. Each box is sold at least one roll, and each roll has the same biasing piece magnetization direction. The ratio of signing is 50% - 100%.