Intaglio composite printing plate and production method and intaglio composite printing plate for banknote printing

Abstract

The present application relates to the technical field of intaglio printing, and particularly relates to an intaglio composite plate, a production method thereof and an intaglio composite plate for banknote printing. The intaglio composite plate provided by the present application comprises a carving layer and a support layer, wherein the carving layer is a copper-zinc alloy layer, has good carvability, is easy to be laser carved, and has good presentation effect for fine graphics and texts with high carving difficulty; the support layer is a metal layer with good mechanical properties, has good durability, and enables the intaglio composite plate to meet the needs of high printing volume. Therefore, the intaglio composite plate of the present application has good carvability and durability, and can be used in the printing field with high graphics and text precision and large printing volume, especially in the banknote printing field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intaglio printing, in particular to an intaglio composite plate, a production method thereof and an intaglio composite plate for banknote printing. BACKGROUND

[0002] In the banknote printing industry, a traditional intaglio plate is made by engraving an intaglio plate, electrocasting a convex plate, and then electrocasting an intaglio plate. The current process has the following problems: the process is complicated, and multiple process steps result in a high rate of defective products and waste products; the electrocasting process has poor environmental protection, and the production cost is high.

[0003] In order to overcome the above problems of the traditional process, a laser engraving process is usually used in the related art to make an intaglio plate for banknote printing, and the plate material used is usually a nickel plate. However, it is difficult to laser engrave a nickel plate, and it is difficult to complete laser engraving of fine graphics with a deep depth and a narrow width. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defect of high engraving difficulty when a nickel plate is used to make an intaglio plate for banknote printing by laser engraving in the prior art, so as to provide an intaglio composite plate, a production method thereof and an intaglio composite plate for banknote printing.

[0005] To this end, the present application provides an intaglio composite plate, which comprises an engraving layer and a support layer, the engraving layer is a copper-zinc alloy layer, and the support layer is a metal layer with a Vickers hardness of 190-230 HV.

[0006] Optionally, the support layer is selected from at least one of a stainless steel layer, a nickel layer, a nickel-based alloy layer, an aluminum alloy layer and a titanium alloy layer, and is preferably a nickel layer;

[0007] Optionally, in the copper-zinc alloy layer, the weight ratio of copper to zinc is (59-68):(30-40).

[0008] Optionally, the intaglio composite plate further comprises a transition layer between the engraving layer and the support layer, and the transition layer contains at least part of aluminum oxide;

[0009] Optionally, the thickness of the transition layer is 0.005-0.05 mm.

[0010] Optionally, the thickness of the intaglio composite plate is 0.74-0.75 mm;

[0011] Optionally, the thickness of the engraving layer is 0.2-0.3 mm, and the thickness of the support layer is 0.45-0.54 mm.

[0012] Optionally, the transition layer is formed by penetration combination of the engraved layer and the support layer after aluminum powder is melted in air and cooled.

[0013] Optionally, after the gravure composite plate is continuously and repeatedly bent at a bending angle of 180°-270° for at least 9 times, the engraved layer and the support layer do not appear to be peeled off.

[0014] Optionally, after the gravure composite plate is bent at a bending angle of 180° for at least 12 times, the engraved layer and the support layer do not appear to be peeled off.

[0015] Optionally, the overall tensile strength of the gravure composite plate is not less than 410 MPa, the yield strength is not less than 300 MPa, and the elongation after breaking is 19-30%.

[0016] The application further provides a production method of the gravure composite plate, comprising the following operations:

[0017] One surface of the copper-zinc alloy plate and the support metal plate is respectively subjected to roughening treatment, polishing, cleaning and drying to obtain a copper-zinc alloy plate to be compounded and a support metal plate to be compounded with rough surfaces;

[0018] The copper-zinc alloy plate to be compounded and the support metal plate to be compounded are heated and kept warm under vacuum conditions;

[0019] After the keeping warm is completed, the rough surfaces of the copper-zinc alloy plate to be compounded and the support metal plate to be compounded are oppositely arranged and are asynchronously rolled to obtain a hot-rolled composite plate;

[0020] The hot-rolled composite plate is subjected to annealing, cold rolling and temperature leveling.

[0021] Optionally, after the roughening treatment, the roughness Rz of the rough surface of the copper-zinc alloy plate is 18-32 μm, and the roughness Rz of the rough surface of the support metal plate is 18-32 μm.

[0022] Optionally, the thickness of the copper-zinc alloy plate is 1.0-2.2 mm, and the surface roughness Rz is less than or equal to 10 μm; the thickness of the support metal plate is 1.6-3.0 mm, and the surface roughness Rz is less than or equal to 15 μm.

[0023] Optionally, the roughening treatment method is selected from any one of laser etching, ball milling or die pressing.

[0024] Optionally, the cleaning comprises four-stage cleaning, the first-stage cleaning is organic reagent cleaning, the second-stage cleaning is alkali cleaning, the third-stage cleaning is acid cleaning, and the fourth-stage cleaning is water cleaning.

[0025] Optionally, the organic reagent cleaning can be cleaning with petroleum ether and alcohol in sequence; the alkali cleaning can be mixed cleaning with 30-60% sodium hydroxide solution by mass percentage and calcium carbonate powder with particle size ≤200 μm; and the acid cleaning can be cleaning with 5-20% sulfuric acid solution by mass percentage.

[0026] Optionally, the drying is vacuum drying, and the vacuum drying is performed after vacuumizing for 5-10 min and then heating and drying, the vacuum degree is 500-1000 Pa, the drying temperature is 60-100 ℃, and the drying time is 5-10 min.

[0027] Optionally, the heating and heat preservation of the copper-zinc alloy plate to be compounded and the support metal plate to be compounded under vacuum conditions comprises: heating and heat preserving the copper-zinc alloy plate to be compounded and the support metal plate to be compounded at different temperatures respectively under vacuum conditions.

[0028] Optionally, the vacuum degree corresponding to the copper-zinc alloy plate to be compounded is 1.33-5.0 MPa, the temperature after heating is 300-600 ℃, and the heat preservation time is 20-40 min.

[0029] Optionally, the vacuum degree corresponding to the support metal plate to be compounded is 1.33-5.0 MPa, the temperature after heating is 800-1100 ℃, and the heat preservation time is 20-40 min.

[0030] Optionally, before the asynchronous rolling, the production method further comprises the operation of arranging aluminum powder between the oppositely arranged rough surfaces.

[0031] Optionally, the thickness of the arranged aluminum powder is 5-20 μm, and the particle size of the aluminum powder is ≤100 μm.

[0032] Optionally, during the asynchronous rolling, the rolling speed of the support metal plate side roller is 30-200 m / s, the rolling speed of the copper-zinc alloy plate side roller is 30-200 m / s, and the ratio of the rolling speed of the support metal plate side roller to the rolling speed of the copper-zinc alloy plate side roller is (1.1-1.6):1.

[0033] Optionally, the number of times of the asynchronous rolling is 5-10 passes, and the single-pass reduction rate is 5-10%.

[0034] Optionally, the annealing temperature is 500-700 ℃, and the time is 20-60 min.

[0035] Optionally, the number of times of the cold rolling is ≥5 passes, and the single-pass reduction rate is 20-50%.

[0036] Optionally, the temperature rising flattening is flattening after heating to 200-500 ℃ and heat preservation for 5-20 min.

[0037] The present application also provides a banknote printing intaglio composite plate made of the intaglio composite plate according to any one of the preceding embodiments or produced by the production method according to any one of the preceding embodiments.

[0038] Optionally, the intaglio composite plate for banknote printing has laser-engraved graphics on the engraved layer, and the engraved layer and the laser-engraved graphics have a plating film with a thickness of 1-10 microns.

[0039] Optionally, the plating film is selected from any one of a chromium nitride plating film, a pure chromium plating film and a cermet.

[0040] The present application has the following advantages:

[0041] 1. The intaglio composite plate provided by the present application includes an engraved layer and a support layer, wherein the engraved layer is a copper-zinc alloy layer, which has good engravability and is easy to be laser-engraved, and has good presentation effect for fine graphics with high engraving difficulty; the support layer is a metal layer with good mechanical properties, which has good durability, so that the intaglio composite plate can meet the needs of high printing volume. Therefore, the intaglio composite plate of the present application has good engravability and durability, and can be used in the field of printing with high graphic accuracy and large printing volume, especially in the field of banknote printing.

[0042] 2. The intaglio composite plate provided by the present application can directly laser-engrave the copper-zinc alloy layer, and can be directly used for intaglio printing after laser-engraving. Compared with the traditional process, the cumbersome process in graphic production is omitted, on the one hand, the accumulation of defects caused by multiple process steps can be avoided, and the rate of defective products and waste products can be reduced, on the other hand, laser-engraving can significantly enhance the graphic reproduction degree.

[0043] 3. The intaglio composite plate provided by the present application has a transition layer formed by penetration and combination of aluminum powder with the engraved layer and the support layer after melting and cooling in air between the engraved layer and the support layer. The melting and cooling process of the aluminum powder enables the transition layer to play a welding role between the engraved layer and the support layer, thereby significantly improving the bonding strength between the engraved layer and the support layer, further improving the durability of the intaglio composite plate, so that the intaglio composite plate does not deform, break or peel off when used for printing 1 million times.

[0044] 4. The production method of the intaglio composite plate provided by the present application roughens one surface of the copper-zinc alloy plate and the support metal plate respectively before compounding, which can remove oxides and impurities on the compounding surface and increase the friction between the compounding surfaces during rolling, which can significantly increase the engagement strength between the compounding surfaces during rolling, thereby effectively improving the bonding strength between the copper-zinc alloy plate and the support metal plate.

[0045] 5. The production method of the gravure composite plate provided by the present application sets aluminum powder between the rough surfaces of the copper-zinc alloy plate to be compounded and the support metal plate to be compounded before rolling, which can protect the two rough surfaces from being oxidized during the rolling process, and is conducive to the better engagement of the two rough surfaces during the rolling process, and on the other hand, the copper-zinc alloy plate and the support metal plate can melt the aluminum powder, and the melting-cooling process of the aluminum powder can form a transition layer between the copper-zinc alloy plate and the support metal plate, play a welding role, and improve the bonding force of the gravure composite plate.

[0046] 6. The production method of the gravure composite plate provided by the present application adopts asynchronous and different temperature rolling, and optimizes the respective rolling temperature and rolling speed, so that the deformation of the copper-zinc alloy plate and the support metal plate during rolling is more coordinated and consistent, which can not only effectively improve the density and bonding force between the two plate materials, but also ensure the flatness of the composite plate material after rolling (the overall flatness is ≤1 mm), and solve the problem of composite rolling of different plate materials and thin plate materials.

[0047] 7. The production method of the gravure composite plate provided by the present application further comprises the following steps: after the asynchronous rolling is performed to a certain extent, cold rolling is performed to reduce the thickness to the required thickness, which can prevent the plate surface from peeling and cracking when the plate material reaches a relatively thin thickness, and effectively ensure the product yield. DETAILED DESCRIPTION

[0048] The following examples are provided to better further understand the present application, and are not limited to the best mode, and do not limit the content and protection scope of the present application. Any person who obtains any product the same as or similar to the present application under the inspiration of the present application or by combining the present application with other prior art features falls within the protection scope of the present application.

[0049] The specific experimental steps or conditions not mentioned in the examples can be performed according to the conventional experimental steps described in the literature in the art or the operation or conditions. The reagents or instruments not mentioned by the manufacturer are conventional reagent products that can be obtained by purchase.

[0050] Example 1

[0051] The present embodiment provides a production method of a gravure composite plate, which comprises the following operations:

[0052] (1) One surface of the H65 copper-zinc alloy plate with a thickness of 1.7 mm, a width of 550 mm, a length of 800 mm, and a surface roughness Rz≤5 μm is ball milled until the plate surface roughness is uniform, and the roughness Rz=30 μm±2 μm;

[0053] One surface of the N6 nickel plate with a thickness of 2.1 mm, a width of 550 mm, a length of 800 mm, and a surface roughness Rz≤10 μm was ball milled until the plate surface roughness was uniform, with a roughness Rz=30 μm±2 μm;

[0054] (2) After the ball milling was completed, the ball milled rough surface of the copper-zinc alloy plate and the nickel plate were polished using a wax-based polishing paste and a wool polishing wheel, respectively;

[0055] (3) After the polishing was completed, the two polished rough surfaces were washed with organic reagents using petroleum ether and alcohol, respectively, to remove the residual polishing paste and other attachments;

[0056] (4) After the organic reagent washing was completed, the two rough surfaces were washed with an alkali solution using a mixture of 500 mL of a 50% by mass sodium hydroxide solution and 200 g of calcium carbonate powder with a particle size ≤200 μm;

[0057] (5) After the alkali solution washing was completed, the two rough surfaces were washed with an acid solution using 1000 mL of a 10% by mass sulfuric acid solution;

[0058] (6) After the acid solution washing was completed, the two rough surfaces were repeatedly rinsed with deionized water until a uniform "water film" was formed on the rough surfaces, to obtain a copper-zinc alloy plate to be compounded and a nickel plate to be compounded;

[0059] (7) After the deionized water rinsing was completed, the copper-zinc alloy plate to be compounded and the nickel plate to be compounded were placed in a vacuum furnace, vacuum was first applied, and when the maximum vacuum degree value (500 Pa) was reached, the vacuum was maintained for 5 min, and then the temperature was set to 80°C, and the drying was performed for 5 min;

[0060] (8) After the drying was completed, the copper-zinc alloy plate to be compounded was heated to 500°C in the vacuum furnace (3.3 MPa) and was maintained for 20 min, and the nickel plate to be compounded was heated to 950°C in the vacuum furnace (2.0 MPa) and was maintained for 20 min;

[0061] (9) After the maintaining was completed, the rough surface of the nickel plate to be compounded faced upward, the rough surface of the copper-zinc alloy plate to be compounded faced downward, the rough surface of the nickel plate to be compounded was uniformly coated with 10 μm thick aluminum powder (particle size ≤100 μm), and then the two plates were butted and placed on a rolling mill for asynchronous rolling, the rolling speed of the nickel plate side was 60 m / s, the rolling speed of the copper-zinc alloy plate side was 50 m / s (the rolling speed ratio of the nickel plate side to the copper-zinc alloy plate side was 1.2:1), and the rolling was performed for 5 passes, with a reduction rate of 5-10% per pass, to obtain a hot-rolled composite plate with an overall flatness ≤1 mm;

[0062] (10) The hot-rolled composite plate is subjected to intermediate annealing at a temperature of 600°C for 30 minutes, and then is cold-rolled at a reduction of 20-25% per pass until the thickness of the composite plate is 0.75 mm;

[0063] (11) After the cold-rolling is completed, the composite plate is heated to 300°C and held for 5 minutes, is flattened, and is cooled at room temperature to obtain the gravure composite plate.

[0064] The gravure composite plate produced in this example is composed of an engraved layer (0.25 mm), a support layer (0.45 mm), and a transition layer (0.05 mm) between the engraved layer and the support layer, wherein the engraved layer is a copper-zinc alloy layer, the support layer is a nickel layer, and the transition layer is formed by penetration bonding of the copper-zinc alloy layer and the nickel layer after the aluminum powder is melted and cooled in air. The overall tensile strength of the gravure composite plate is 618 MPa, the yield strength is 570 MPa, the elongation after breakage is 19%, and after 16 times of 180° repeated bending to breakage, the engraved layer and the support layer do not peel off.

[0065] Example 2

[0066] The gravure composite plate is produced according to the method of Example 1, except that in this example, after the ball milling in operation (1) is completed, the roughness Rz of the rough surface of the copper-zinc alloy plate is 22-28 μm, and the roughness Rz of the rough surface of the nickel plate is 22-28 μm.

[0067] The overall tensile strength of the gravure composite plate produced in this example is 576 MPa, the yield strength is 512 MPa, the elongation after breakage is 26.3%, and after 15 times of 180° repeated bending to breakage, the engraved layer and the support layer do not peel off.

[0068] Example 3

[0069] The gravure composite plate is produced according to the method of Example 1, except that in this example, after the ball milling in operation (1) is completed, the roughness Rz of the rough surface of the copper-zinc alloy plate is 23-25 μm, and the roughness Rz of the rough surface of the nickel plate is 23-25 μm.

[0070] The overall tensile strength of the gravure composite plate produced in this example is 480 MPa, the yield strength is 456 MPa, the elongation after breakage is 23.1%, and after 14 times of 180° repeated bending to breakage, the engraved layer and the support layer do not peel off.

[0071] Example 4

[0072] The gravure composite plate is produced according to the method of Example 1, except that in this example, after the vacuum heterothermal heating in operation (8) is completed, the temperature of the copper-zinc alloy plate is 300°C, and the temperature of the nickel plate is 1100°C.

[0073] The overall tensile strength of the gravure composite plate prepared in this example is 473 MPa, the yield strength is 344 MPa, the elongation after fracture is 24.8%, and after 14 times of 180° repeated bending to fracture, the engraved layer and the support layer do not appear to peel off.

[0074] Example 5

[0075] The gravure composite plate is produced according to the method of Example 1, except that in the operation (8) of this example, after vacuum heterothermal heating, the temperature of the copper-zinc alloy plate is 600°C, and the temperature of the nickel plate is 800°C.

[0076] The overall tensile strength of the gravure composite plate prepared in this example is 491 MPa, the yield strength is 307 MPa, the elongation after fracture is 29.7%, and after 13 times of 180° repeated bending to fracture, the engraved layer and the support layer do not appear to peel off.

[0077] Example 6

[0078] The gravure composite plate is produced according to the method of Example 1, except that in the operation (9) of this example, the coating thickness of the aluminum powder is 5 μm.

[0079] The overall tensile strength of the gravure composite plate prepared in this example is 431 MPa, the yield strength is 365 MPa, the elongation after fracture is 27.6%, and after 12 times of 180° repeated bending to fracture, the engraved layer and the support layer do not appear to peel off.

[0080] Example 7

[0081] The gravure composite plate is produced according to the method of Example 1, except that in the operation (9) of this example, the coating thickness of the aluminum powder is 20 μm.

[0082] The overall tensile strength of the gravure composite plate prepared in this example is 541 MPa, the yield strength is 434 MPa, the elongation after fracture is 24.3%, and after 17 times of 180° repeated bending to fracture, the engraved layer and the support layer do not appear to peel off.

[0083] Example 8

[0084] The gravure composite plate is produced according to the method of Example 1, except that in the operation (9) of this example, the coating thickness of the aluminum powder is 25 μm.

[0085] The overall tensile strength of the gravure composite plate prepared in this example is 583 MPa, the yield strength is 491 MPa, the elongation after fracture is 25.4%, and after 15 times of 180° repeated bending to fracture, the engraved layer and the support layer do not appear to peel off.

[0086] Example 9

[0087] The gravure composite plate was produced according to the method of Example 1, except that in operation (9) of this example, the rolling speed of the nickel plate side roller was 60 m / s and the rolling speed of the copper-zinc alloy plate side roller was 45 m / s (the ratio of the rolling speed of the nickel plate side to that of the copper-zinc alloy plate side was 1.33:1) during the asynchronous rolling.

[0088] The gravure composite plate produced in this comparative example had an overall tensile strength of 442 MPa, a yield strength of 380 MPa, and an elongation at break of 26.4%. After being repeatedly bent at 180° for 13 times until it was broken, the engraved layer and the support layer did not peel off.

[0089] Example 10

[0090] The gravure composite plate was produced according to the method of Example 1, except that in operation (9) of this example, the rolling speed of the nickel plate side roller was 60 m / s and the rolling speed of the copper-zinc alloy plate side roller was 45 m / s (the ratio of the rolling speed of the nickel plate side to that of the copper-zinc alloy plate side was 1.33:1) during the asynchronous rolling.

[0091] The gravure composite plate produced in this example had an overall tensile strength of 661 MPa, a yield strength of 611 MPa, and an elongation at break of 24.7%. After being repeatedly bent at 180° for 13 times until it was broken, the engraved layer and the support layer did not peel off.

[0092] Example 11

[0093] The gravure composite plate was produced according to the method of Example 1, except that in operation (9) of this example, the rolling speed of the nickel plate side roller was 60 m / s and the rolling speed of the copper-zinc alloy plate side roller was 37 m / s (the ratio of the rolling speed of the nickel plate side to that of the copper-zinc alloy plate side was 1.6:1) during the asynchronous rolling.

[0094] The gravure composite plate produced in this example had an overall tensile strength of 636 MPa, a yield strength of 523 MPa, and an elongation at break of 29.3%. After being repeatedly bent at 180° for 20 times until it was broken, the engraved layer and the support layer did not peel off.

[0095] Example 12

[0096] The gravure composite plate was produced according to the method of Example 1, except that in this example, a stainless steel plate of 304 brand with a thickness of 5 mm, a width of 550 mm, a length of 800 mm, and a surface roughness Rz≤30 μm was used to replace the nickel plate.

[0097] In this example, the support layer of the gravure composite plate was a stainless steel layer. The gravure composite plate had an overall tensile strength of 676 MPa, a yield strength of 583 MPa, and an elongation at break of 29.6%. After being repeatedly bent at 180° for 16 times until it was broken, the engraved layer and the support layer did not peel off.

[0098] Example 13

[0099] The intaglio composite plate was produced according to the method of Example 1, except that in operation (8) of this example, the temperature of the copper-zinc alloy plate and the nickel plate after vacuum heating was 500℃.

[0100] The intaglio composite plate produced in this example had a tensile strength of 490 MPa, a yield strength of 411 MPa, and an elongation at break of 23.5%. After 14 times of 180° repeated bending to breakage, the engraved layer and the support layer peeled off.

[0101] Comparative Example 1

[0102] The intaglio composite plate was produced according to the method of Example 1, except that in operation (9) of this comparative example, synchronous rolling was used, and the rolling speed of the roller was 60 m / s.

[0103] In the intaglio composite plate produced in this comparative example, there were visible gaps between the engraved layer and the support layer, and the engraved layer and the support layer peeled off after 5 times of 180° repeated bending.

[0104] Comparative Example 2

[0105] The intaglio composite plate was produced according to the method of Example 1, except that in operation (9) of this comparative example, synchronous rolling was used, and the rolling speed of the roller was 50 m / s.

[0106] In the intaglio composite plate produced in this comparative example, there were visible gaps between the engraved layer and the support layer, and the engraved layer and the support layer peeled off after 4 times of 180° repeated bending.

[0107] Experimental Example

[0108] The intaglio composite plates produced in Examples 1-13 and copper-zinc alloy plates with a thickness of 0.75 mm and electroplated nickel plates with a thickness of 0.75 mm were laser engraved, and after the graphic expression was completed, 3 μm thick chromium nitride was sputtered on the graphic surface by magnetron sputtering to obtain intaglio plates for banknote printing. The intaglio plates were fixed on a printing machine, and the graphic expression was transferred to the printing material by ink to complete printing. Each intaglio plate was repeatedly printed multiple times, and the maximum printing times of each intaglio plate were counted when breakage, deformation or separation occurred. Each intaglio plate was repeatedly tested for 3 times, and the average value of the maximum printing times of each intaglio plate was calculated, as shown in Table 1.

[0109] Table 1 Average value of the maximum printing times of each intaglio plate

[0110]

[0111] As can be seen from Table 1, the intaglio composite plate of the present application has good engravability and durability, and can be used in the field of high-precision graphic expression and large printing volume, especially in the field of banknote printing.

[0112] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and can not be enumerated. The obvious changes or variations derived from the above description are still within the protection scope of the present application.

Claims

1. A gravure printing composite plate for banknote printing, characterized in that, The gravure printing composite plate includes an engraving layer and a support layer, and the gravure printing composite plate also includes a transition layer located between the engraving layer and the support layer; the engraving layer is a copper-zinc alloy layer, and the support layer is a metal layer with a Vickers hardness of 190-230 HV; The intaglio composite plate has a transition layer between the engraving layer and the support layer, which is formed by aluminum powder being melted and cooled in the air and then permeating and bonding with the engraving layer and the support layer. The support layer is a nickel layer; The engraving layer of the intaglio printing composite plate for banknote printing has laser-engraved graphics, and the surface of the engraving layer and the laser-engraved graphics is coated with a film with a thickness of 1 to 10 μm. The coating is selected from any one of chromium nitride coating, pure chromium coating, and cermet; The method for producing the gravure composite plate includes the following operations: One surface of the copper-zinc alloy plate and the supporting metal plate are respectively roughened, polished, cleaned and dried to obtain a copper-zinc alloy plate and a supporting metal plate to be composited with roughened surfaces; the roughness Rz of the roughened surface of the copper-zinc alloy plate is 18~32μm, and the roughness Rz of the roughened surface of the supporting metal plate is 18~32μm. The copper-zinc alloy plate to be laminated and the supporting metal plate to be laminated are heated and held at a temperature under vacuum conditions; the vacuum degree corresponding to the copper-zinc alloy plate to be laminated is 1.33-5.0 MPa, the temperature after heating is 300-600℃, and the holding time is 20-40 min; the vacuum degree corresponding to the supporting metal plate to be laminated is 1.33-5.0 MPa, the temperature after heating is 800-1100℃, and the holding time is 20-40 min. After the heat preservation is completed, the rough surfaces of the copper-zinc alloy plate to be composited and the supporting metal plate to be composited are set opposite each other and asynchronously rolled to obtain a hot-rolled composite plate. The hot-rolled composite plate is annealed, cold-rolled, and heated to level. Prior to asynchronous rolling, the production method further includes the operation of setting aluminum powder between relatively rough surfaces; The thickness of the aluminum powder is 5-20 μm, and the particle size of the aluminum powder is ≤100 μm; During asynchronous rolling, the rolling speed of the supporting metal plate side roll is 30-60 m / s, and the rolling speed of the copper-zinc alloy plate side roll is 45-50 m / s. The ratio of the rolling speed of the supporting metal plate side roll to the rolling speed of the copper-zinc alloy plate side roll is (1.1-1.33):

1.

2. The intaglio printing composite plate for banknote printing according to claim 1, characterized in that, In the copper-zinc alloy layer, the weight ratio of copper to zinc is (59-68):(30-40).

3. The gravure composite plate according to claim 1 or 2, characterized in that, The transition layer contains at least a portion of aluminum oxide; The thickness of the transition layer is 0.005 to 0.05 mm.

4. The intaglio printing composite plate for banknote printing according to claim 1 or 2, characterized in that, The thickness of the gravure printing composite plate is 0.74–0.75 mm; The thickness of the engraved layer is 0.2–0.3 mm; the thickness of the support layer is 0.45–0.54 mm.

5. The intaglio printing composite plate for banknote printing according to claim 1, characterized in that, After roughening treatment, the thickness of the copper-zinc alloy plate is 1.0–2.2 mm, and the surface roughness Rz ≤ 10 μm; the thickness of the supporting metal plate is 1.6–3.0 mm, and the surface roughness Rz ≤ 15 μm. The roughening method is selected from any one of laser etching, ball milling, or molding. The cleaning process includes four stages: the first stage is organic reagent cleaning, the second stage is alkaline cleaning, the third stage is acid cleaning, and the fourth stage is water cleaning. The drying process is vacuum drying, which involves drawing a vacuum and maintaining it for 5 to 10 minutes before heating and drying. The vacuum level is 500 to 1000 Pa, the drying temperature is 60 to 100°C, and the drying time is 5 to 10 minutes.

6. The intaglio printing composite plate for banknote printing according to claim 1, characterized in that, The asynchronous rolling process is performed in 5 to 10 passes, with a reduction rate of 5 to 10% per pass. The annealing temperature is 500–700℃, and the time is 20–60 min; The number of cold rolling passes is ≥5, and the reduction rate per pass is 20-50%. The heating and leveling process involves heating to 200–500°C, holding at that temperature for 5–20 minutes, and then flattening.

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