High-stability gravure ink and preparation device thereof

Abstract

The invention discloses high-stability gravure ink and a preparation device thereof, and belongs to the technical field of printing materials, and the ink is prepared from polyurethane acrylate hybrid resin, phthalocyanine blue pigment, nano-zinc oxide dispersion, environment-friendly ester solvent, isopropanol and a plurality of auxiliaries according to a specific weight part ratio. The anti-settling property, the leveling property and the storage stability are excellent. The preparation device comprises an intelligent batching unit, a multi-stage efficient mixing and dispersing unit, a vacuum defoaming and curing unit and an online filtering and filling unit which are sequentially arranged in the material flow direction, and is integrally controlled by a central intelligent control system. According to the device, through the unique coaxial different-direction stirring assembly, ultrasonic-assisted dispersion and full-process automatic control, efficient, uniform and continuous production of printing ink is achieved, and the consistency of product quality and production efficiency are remarkably improved. The problems that traditional gravure ink is poor in stability, the production process is dispersed, and the traditional gravure ink depends on manpower are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printing materials, in particular to a high-stability gravure ink and a special preparation device thereof. BACKGROUND

[0002] Gravure printing is widely used in high-quality printing fields such as food packaging, tobacco and liquor packaging, and publications due to its thick ink layer, bright color, high saturation, and high printing plate durability. Gravure ink is a key material for gravure printing, and its performance directly affects the quality and production efficiency of the printed product.

[0003] Currently, traditional gravure inks generally have poor stability, which is manifested in that the pigments are prone to sedimentation and caking during storage and transportation, resulting in a decrease in the uniformity of the ink, frequent stirring during use, and an increase in process complexity. The bubbles in the ink system are difficult to eliminate, affecting the flatness and smoothness of the printed surface. The solvent evaporation speed is not properly controlled, which may cause poor leveling and other problems. These factors not only reduce the printing efficiency, but also may cause an increase in the rate of defective products.

[0004] In addition, existing ink production equipment often has poor connection between process units and low automation, and relies on manual experience for proportioning and process control, thereby leading to poor product quality stability between batches, low production efficiency, and difficulty in meeting the modern production demands of high quality and high efficiency.

[0005] Therefore, it is of great significance to develop a gravure ink with high stability and excellent performance, as well as an automatic and continuous preparation device thereof. SUMMARY

[0006] 1. Technical problem to be solved In view of the problems in the prior art, one of the purposes of the present application is to overcome the shortcomings of the prior art and provide a gravure ink that is resistant to sedimentation, has good leveling, complete defoaming, and high storage stability.

[0007] Another purpose of the present application is to provide an automatic preparation device for preparing the above-mentioned ink, which can realize continuous and intelligent production from proportioning to filling, and effectively ensure the uniformity and stability of product quality.

[0008] 2. Technical scheme To solve the above-mentioned problems, the present application adopts the following technical scheme.

[0009] In a first aspect, the present application provides a high-stability gravure ink, which is made of raw materials including the following weight parts: 25-35 parts of polyurethane acrylate hybrid resin; 10-15 parts of phthalocyanine blue pigment; Nanometer zinc oxide dispersion 1-3 parts; Environment-friendly ester solvent 40-50 parts; Isopropyl alcohol 5-10 parts; Anti-precipitation agent 0.5-1.5 parts; Leveling agent 0.3-0.8 parts; Defoaming agent 0.2-0.5 parts.

[0010] Preferably, the number average molecular weight of the polyurethane acrylate hybrid resin is 25000-35000.

[0011] Preferably, the environment-friendly ester solvent is n-propyl acetate or butyl acetate.

[0012] Preferably, the anti-precipitation agent is an organic modified bentonite.

[0013] Preferably, the solid content of the nanometer zinc oxide dispersion is 40%-60%.

[0014] In a second aspect, the present application provides a preparation device for preparing the high-stability gravure ink, comprising, in sequence along the material flow direction, an intelligent batching unit, a multi-stage efficient mixing and dispersion unit, a vacuum degassing and curing unit, and an online filtering and filling unit, all of which are connected and controlled by a central intelligent control system. The discharge port of the intelligent batching unit is connected to the feed port of the multi-stage efficient mixing and dispersion unit through a conveying pipeline, the discharge port of the multi-stage efficient mixing and dispersion unit is connected to the feed port of the vacuum degassing and curing unit through a conveying pump, and the discharge port of the vacuum degassing and curing unit is connected to the feed port of the online filtering and filling unit through a conveying pump.

[0015] Preferably, the intelligent batching unit comprises a plurality of raw material storage tanks, the support structures at the bottoms of which are each provided with a weighing sensor, and the outlets of which are each connected to a pneumatic valve and a conveying pump; the raw material storage tanks comprise: A first type of storage tank for storing resin materials, which is a vertical tank body with a jacketed heat preservation and an overhead stirrer; A second type of storage tank for storing solvents, which is provided at the top with a breather valve and a nitrogen sealing device; A third type of storage tank for storing pigment paste, which is a vertical tank body with a jacketed heat preservation, and a side-entering stirrer mounted on the sidewall of the tank body.

[0016] Preferably, the multi-stage efficient mixing and dispersion unit comprises a main reaction kettle, which is provided with a coaxial counter-rotating stirring assembly; the outer wall of the main reaction kettle is integrated with an ultrasonic auxiliary dispersion system; the main reaction kettle is also integrated with an online viscosity sensor and a temperature sensor for real-time detection of the viscosity of the material.

[0017] Preferably, the coaxial and opposite stirring assembly comprises a housing mounted above the main reactor, a top transmission disc and a bottom transmission disc are rotatably connected in the housing, and the top transmission disc and the bottom transmission disc are driven to rotate reversely through the meshing of transmission gear one and transmission gear two fixed in the middle of the housing; the bottom of the top transmission disc is connected with a through rod, the bottom of the bottom transmission disc is connected with a hollow cylinder, the through rod extends into the hollow cylinder, and the bottom of the through rod and the bottom of the hollow cylinder are respectively provided with a stirring paddle; a driving motor is connected above the top transmission disc.

[0018] Preferably, the vacuum defoaming and curing unit comprises a vacuum defoaming tank, the vacuum defoaming tank is connected with a vacuum pump set, and a slow anchor type stirrer is arranged in the top of the vacuum defoaming tank.

[0019] Preferably, the online filtering and filling unit comprises a bag filter and a candle type precision filter which are connected in sequence through pipelines, and the outlet of the candle type precision filter is connected to a full-automatic filling machine through a pipeline.

[0020] Preferably, the central intelligent control system comprises a programmable logic controller (PLC) and an upper computer human-machine interface (HMI), the PLC is electrically connected with and controls the execution devices, sensors and pumps and valves in each unit, and the HMI is integrated with a manufacturing execution system (MES) interface, which is used for inputting formula parameters, displaying real-time process curves, alarm information and realizing production data tracing.

[0021] 3. Beneficial effects: Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects: (1) In terms of ink products: through the combination of specific components and proportions, especially by using high molecular weight polyurethane acrylate hybrid resin as a connecting material, and by compounding nano zinc oxide dispersion, organic modified bentonite and other additives, the stability of the ink is significantly improved, pigment settlement and caking are effectively prevented, excellent leveling and defoaming performance are ensured, and printing suitability is good.

[0022] (2) In terms of preparation device: Through full-process automation and intelligent control, integrated management by the central intelligent control system, precise batching, efficient dispersion, vacuum defoaming, online filtering and filling are realized in the full-closed continuous production, the production efficiency and product consistency are greatly improved, and human error and external pollution are reduced.

[0023] The multi-stage high-efficiency mixing and dispersing unit is designed with a unique coaxial and opposite stirring structure, and combined with ultrasonic assisted dispersion, can generate strong shearing, extrusion and vortex effect, greatly improving the dispersion efficiency and uniformity of pigments and resins, and shortening the dispersion time.

[0024] The intelligent batching unit is designed according to the material characteristics, and a storage tank (heat preservation, stirring, nitrogen sealing) is arranged in different zones, so that the stability of the raw materials before being put in is ensured; the vacuum degassing and curing unit is under low-speed stirring, vacuum is extracted, micro-bubbles are completely eliminated, the system curing is promoted, and the final quality of the ink is improved.

[0025] It should be noted that the structures not introduced in the present application are the same as the prior art or can be realized by using the prior art, and do not need to be described here. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structure schematic diagram of the whole preparation device of the present application; Figure 2 It is a structure schematic diagram of the intelligent batching unit of the present application; Figure 3 It is a structure schematic diagram of the side-entering stirrer of the present application Figure 4 It is a structure schematic diagram of the multi-stage high-efficiency mixing and dispersing unit, wherein a coaxial and opposite-direction stirring assembly is shown; Figure 5 It is a structure schematic diagram of the vacuum degassing and curing unit and the online filtering and filling unit; Figure 6 It is a performance test result table of the ink finished products obtained in examples 1 and 2 of the present application.

[0027] Explanation of the reference numerals in the drawing: 100, intelligent batching unit; 101, raw material storage tank; 101a, first type storage tank; 101b, second type storage tank; 101c, third type storage tank; 102, top-mounted stirrer; 103, weighing sensor; 104, nitrogen sealing device; 105, side-entering stirrer; 200, multi-stage high-efficiency mixing and dispersing unit; 201, main reaction kettle; 202, coaxial and opposite-direction stirring assembly; 2021, shell; 2022, upper transmission disc; 2023, lower transmission disc; 2024, transmission gear one; 2025, transmission gear two; 2026, through rod; 2027, hollow cylinder; 2028, stirring paddle; 2029, driving motor; 300, vacuum degassing and curing unit; 301, vacuum degassing tank; 302, slow-speed anchor stirrer; 400, online filtering and filling unit; 401, bag filter; 402, candle type precision filter; 403, full-automatic filling machine. DETAILED DESCRIPTION

[0028] In order to make a detailed description of the present application in combination with the drawings and specific embodiments below, the technical solutions and beneficial effects of the present application are fully demonstrated, but the protection scope of the present application should not be limited to this.

[0029] Example 1: Preparation of a high-stability blue intaglio ink This example details the operation process of the ink of the present application and its preparation device.

[0030] 1. Raw material ratio (by weight): Polyurethane acrylate hybrid resin (number average molecular weight Mn≈30000): 30 parts Phthalocyanine blue pigment (BGS series): 12 parts Nanometer zinc oxide dispersion (solid content 50%): 2 parts Environment-friendly ester solvent (n-propyl acetate): 45 parts Isopropanol: 7 parts Anti-settling agent (organically modified bentonite, such as Bentone SD series): 1.0 part Leveling agent (polyether-modified polydimethylsiloxane, such as BYK-333): 0.5 part Defoaming agent (polysiloxane solution, such as TEGO Airex 900): 0.3 part 2. Preparation process: (1) Intelligent batching stage: The operator logs in to the MES system through the upper computer human-machine interface (HMI) of the central intelligent control system, retrieves and issues the production instruction of "blue intaglio ink-formulation 01".

[0031] After receiving the instruction, the PLC controller first controls the pneumatic valve and delivery pump of the second type of storage tank (101b) to deliver the accurately measured n-propyl acetate (25 parts) and isopropanol (7 parts) to the main reaction kettle (201) as the undercoat solvent. The weighing sensor (103) feedbacks the data in real time, and the PLC automatically closes the valve when the delivery amount reaches the set value.

[0032] Subsequently, the PLC controls the overhead stirrer (102) of the first type of storage tank (101a) to start (speed 50 rpm), and at the same time opens the pneumatic valve and delivery pump to stably deliver the polyurethane acrylate hybrid resin (30 parts) preheated to 45°C (maintained by jacket heating) to the main reaction kettle.

[0033] Finally, the PLC controls the side-entering stirrer (105) of the third type of storage tank (101c) to start (speed 100 rpm) to deliver the pre-dispersed phthalocyanine blue pigment paste (12 parts) to the main reaction kettle.

[0034] (2) High-efficiency mixing and dispersion stage: After all the liquid raw materials are fed, the coaxial and opposite stirring assembly (202) of the main reactor (201) is started. The driving motor (2029) drives the upper transmission disc (2022) to rotate clockwise at a speed of 1200 rpm.

[0035] Through the meshing of the first transmission gear (2024) and the second transmission gear (2025), the lower transmission disc (2023) is driven to rotate counterclockwise at a speed of 800 rpm. This makes the through rod (2026) and the stirring paddle (2028) at the bottom of the hollow cylinder (2027) form a strong and opposite shear force field, and the material is dispersed at high speed. This stage lasts for 15 minutes, and the temperature in the kettle is controlled below 40°C by jacket cooling water.

[0036] Subsequently, the ultrasonic auxiliary dispersion system integrated in the kettle wall (power 1.5 kW, frequency 25 kHz) is started, and the stirring speed is reduced to 800 rpm, and the dispersion is continued for 30 minutes. During this process, the nano zinc oxide dispersion (2 parts) is added through the auxiliary material inlet.

[0037] The online viscosity sensor monitors the material viscosity in real time, and when the system detects that the viscosity value reaches the preset range (3500±200 cP in this embodiment) and stabilizes for 5 minutes, the PLC determines that the dispersion is completed.

[0038] (3) Vacuum defoaming and curing stage: The dispersed slurry is transferred to the vacuum defoaming tank (301) by the transfer pump. Then the slow anchor type stirrer (302) (speed 30 rpm) is started to ensure uniform heating of the material.

[0039] The vacuum pump set is started, and the vacuum degree in the tank is gradually increased to-0.098 MPa in stages, which takes about 10 minutes to prevent boiling. Keep at this vacuum degree for 40 minutes to completely remove the fine bubbles entrained by the material in the high-speed dispersion stage.

[0040] After defoaming, under the conditions of slow stirring and micro vacuum (-0.05 MPa), anti-settling agent (1.0 parts), leveling agent (0.5 parts) and defoaming agent (0.3 parts) are added in turn, and continue to cure for 60 minutes. Make the auxiliary agent fully play its role, and the system reaches the final stable state.

[0041] (4) Online filtration and filling stage: The cured ink is sent out by the transfer pump, first passes through the bag filter (401) (400 mesh filter bag is selected) for rough filtration to remove possible extremely small amount of agglomerates.

[0042] Then the ink enters the candle type precision filter (402) (10 μm precision filter element is selected) for precision filtration to ensure the purity of the product.

[0043] Finally, the high-quality ink obtained enters a full-automatic filling machine (403) to perform metering filling (1 kg / can) under nitrogen protection and is automatically capped and labeled. Data of the entire production process, such as process parameters, quality data (final viscosity value, filling amount), etc., are recorded and uploaded to an MES system to realize full-process tracing.

[0044] Example 2: Formula adjustment example To show the adjustability of the formula of the present application, another example is provided, which has the same preparation process as example 1, only the proportion of raw materials is adjusted: Polyurethane acrylate hybrid resin (Mn = 28000): 28 parts Phthalocyanine blue pigment: 14 parts Nano zinc oxide dispersion: 1.5 parts Butyl acetate: 48 parts Isopropyl alcohol: 5 parts Organically modified bentonite: 1.2 parts Leveling agent: 0.6 parts Defoaming agent: 0.4 parts This formula can also prepare a gravure ink with excellent stability and printing performance.

[0045] Comparative example: An ink with the same formula as example 1 is prepared using a traditional high-speed disperser (not the device of the present application), and there is no vacuum defoaming and online filtering process. After the product is stored for two weeks, there is obvious pigment sedimentation and hardening at the bottom of the tank, and pinholes and poor leveling occur during printing test.

[0046] In summary, the high-stability gravure ink and its preparation device provided by the present application can significantly improve the dispersion fineness, storage stability and final printing effect of the product, and the batch consistency is excellent.

[0047] The above examples only express certain embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the present patent; it should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application; therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. A highly stable gravure printing ink, characterized in that, Made from the following parts by weight of raw materials: 25-35 parts of polyurethane acrylate hybrid resin; 10-15 parts of phthalocyanine blue pigment; 1-3 parts of nano zinc oxide dispersion; 40-50 parts of environmentally friendly ester solvent; 5-10 parts isopropanol; Anti-precipitant 0.5-1.5 parts; Leveling agent 0.3-0.8 parts; 0.2-0.5 parts of defoamer.

2. The high-stability gravure ink according to claim 1, characterized in that, The number average molecular weight of the polyurethane acrylate hybrid resin is 25,000-35,000.

3. The high-stability gravure printing ink according to claim 1, characterized in that, The environmentally friendly ester solvent is n-propyl acetate or butyl acetate, and the anti-precipitant is organically modified bentonite.

4. An apparatus for preparing highly stable gravure printing ink, characterized in that, It includes an intelligent batching unit (100), a multi-stage high-efficiency mixing and dispersing unit (200), a vacuum degassing and maturation unit (300), and an online filtration and filling unit (400) arranged sequentially along the material flow direction. Each unit is connected and controlled by a central intelligent control system. The outlet of the intelligent batching unit (100) is connected to the inlet of the multi-stage high-efficiency mixing and dispersing unit (200) through a conveying pipe; The outlet of the multi-stage high-efficiency mixing and dispersing unit (200) is connected to the inlet of the vacuum degassing and maturation unit (300) via a delivery pump; The outlet of the vacuum degassing and curing unit (300) is connected to the inlet of the online filtration and filling unit (400) via a delivery pump.

5. The apparatus for preparing a high-stability gravure printing ink according to claim 4, characterized in that, The intelligent batching unit (100) includes several raw material storage tanks (101), each raw material storage tank (101) is equipped with a weighing sensor (103) at the bottom and a pneumatic valve and a delivery pump at the outlet; The raw material storage tank (101) includes: The first type of storage tank (101a) is used to store resin materials and is equipped with a jacketed insulation structure and a top-mounted agitator (102). The second type of storage tank (101b) is used to store solvents and is equipped with a breather valve and nitrogen sealing device (104) on the top. The third type of storage tank (101c) is used to store pigment paste and is equipped with a jacketed insulation structure and a side-entry agitator (105).

6. The apparatus for preparing a high-stability gravure printing ink according to claim 4, characterized in that, The multi-stage high-efficiency mixing and dispersing unit (200) includes a main reactor (201), and the main reactor (201) is equipped with a coaxial counter-rotating stirring assembly (202). The outer wall of the main reactor (201) is integrated with an ultrasonic-assisted dispersion system; The main reactor (201) is also equipped with an online viscosity sensor and a temperature sensor.

7. The apparatus for preparing a high-stability gravure printing ink according to claim 6, characterized in that, The coaxial counter-rotating stirring assembly (202) includes: The housing (2021) has an upper transmission disc (2022) and a lower transmission disc (2023) rotatably connected inside it. Transmission gear one (2024) and transmission gear two (2025) are fixed to the inner wall of the middle part of the housing and are used to drive the upper transmission disk and the lower transmission disk to rotate in opposite directions; The bottom of the upper transmission disc (2022) is connected to a through rod (2026), and the bottom of the lower transmission disc (2023) is connected to a hollow cylinder (2027). The through rod (2026) extends into the hollow cylinder (2027), and both are provided with stirring paddles (2028) at their bottoms. A drive motor (2029) is connected above the upper transmission disk (2022).

8. The apparatus for preparing a high-stability gravure ink according to claim 4, characterized in that, The vacuum degassing and maturation unit (300) includes a vacuum degassing tank (301), which is connected to a vacuum pump group and has a slow anchor stirrer (302) on top.

9. The apparatus for preparing a high-stability gravure printing ink according to claim 4, characterized in that, The online filtration and filling unit (400) includes a bag filter (401) and a candle filter (402) connected in series, with the outlet of the candle filter (402) connected to a fully automatic filling machine (403).

10. The apparatus for preparing a high-stability gravure ink according to claim 4, characterized in that, The central intelligent control system includes a PLC controller and a host computer human-machine interface. The PLC controller is electrically connected to and controls the actuators, sensors and pumps / valve of each unit. The host computer human-machine interface integrates an MES system interface for formula parameter input, real-time process curve display, alarm information prompts, and production data traceability.

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