Calibration material

Abstract

The utility model discloses a correcting and printing material which comprises a substrate layer and a movable layer which are arranged in a stacked mode, and the substrate layer is selected from any one of paper, a macromolecule sheet, a metal sheet and a composite material. The movable layer comprises a water-based film-forming substance, the water-based film-forming substance can be thermally dissociated in a specific environment, and after the water-based film-forming substance is thermally dissociated, the movable layer can be removed. When the correcting and printing material is used for correcting and printing, the substrate layer can be repeatedly used after the movable layer is removed, so that the correcting and printing cost of a printing enterprise is greatly reduced. The preparation method of the calibration material is used for preparing the calibration material, and the coating removing method is used for removing the movable layer.

Description

Technical Field

[0001] This utility model relates to the field of materials technology, and in particular to a proofing material. Background Technology

[0002] In existing technologies, coatings containing water-based film-forming substances (such as water-based varnishes) are widely used in the surface treatment of printed materials. These coatings protect the printed graphics by forming a protective layer. Since printed materials may experience high temperatures and humidity in summer warehouses or shipping containers, the coatings must possess high stability, including excellent resistance to high-temperature dissociation and moisture resistance. Failure to meet these performance standards can lead to serious quality issues. To verify stability, anti-tack tests are typically conducted at 70°C and 90% humidity. Therefore, preventing thermal dissociation of water-based film-forming substance coatings at high temperatures is a technical problem that those skilled in the art must overcome.

[0003] In the existing technology, foamed materials are widely used in the clothing industry to prepare foamed patterns. Since clothing needs to be in contact with water for a long time and undergo a lot of friction during the washing process, the foamed patterns are required to have good adhesion and water resistance. If the above properties are not up to standard, it will lead to quality accidents.

[0004] In offset printing, gravure printing, screen printing, or flexographic printing processes, the image layer formed by the printing ink is in direct contact with the proofing material. The ink has the characteristics of permeability, thin ink layer and high adhesion. Therefore, the image layer on the proofing material cannot be removed. This results in a large amount of proofing material used in the printing process not being reusable, which increases the cost pressure on printing companies.

[0005] Therefore, it is necessary to provide a proofreading material to solve the above problems. Utility Model Content

[0006] A proofreading material, comprising:

[0007] The base layer is selected from any one of paper, polymer sheets, metal sheets, and composite materials; and

[0008] A movable layer is stacked on the substrate layer. The movable layer contains an aqueous film-forming substance that can undergo thermal dissociation under specific conditions. After the aqueous film-forming substance undergoes thermal dissociation, the movable layer can be removed.

[0009] In one embodiment, the aqueous film-forming substance is selected from at least one of polyurethane resin, acrylic resin, polyvinyl alcohol and its modified resins, polyethylene oxide resin, starch and its derivatives, polyvinylpyrrolidone, and environmentally responsive block copolymers.

[0010] In one embodiment, the specific environment is a wet heating environment, and the thermal dissociation is thermal swelling dissociation.

[0011] In one embodiment, the removable layer comprises a foamed material.

[0012] In one embodiment, the specific environment is a dry heating environment, and the thermally induced dissociation is thermally induced fracture dissociation.

[0013] In one embodiment, the specific environment is a wet heating environment, and the thermal dissociation is thermal swelling dissociation and thermal cracking dissociation.

[0014] In one embodiment, the specific environment is a steam-heated environment, and the thermal dissociation is moderately thermally induced swelling dissociation and fully thermally induced rupture dissociation.

[0015] In one embodiment, the specific environment successively includes a dry heating environment and a wet heating environment, and the thermally induced dissociation successively includes low-limit thermally induced cracking dissociation and moderate-limit thermally induced swelling dissociation.

[0016] In one embodiment, the foaming material is selected from at least one of physical foaming materials, chemical foaming materials, inorganic foaming materials, environmentally friendly foaming materials, and composite foaming materials.

[0017] In one embodiment, the physical foaming material is selected from any one of volatile liquids, compressed gases, supercritical fluids, foamed microspheres, expanded graphite, vermiculite powder, and expanded hexagonal boron nitride; the chemical foaming material is selected from any one of azo foaming materials, sulfonyl hydrazine foaming materials, carbonate foaming materials, hydrazine / acyl hydrazine foaming materials, hydrazine / acyl hydrazine foaming materials, and reactive foaming materials; the inorganic foaming material is selected from any one of carbonate foaming materials, metal hydride foaming materials, and silicate foaming materials; the environmentally friendly foaming material is selected from any one of bio-based foaming materials, HFOs foaming materials, and natural product foaming materials; and the composite foaming material is selected from any one of endothermic-exothermic composite foaming materials, acid-base reactive foaming materials, and metal-organic composite foaming materials.

[0018] In one embodiment, the foaming material has a specific induction temperature, which is 60°C-200°C.

[0019] In one embodiment, the thickness of the movable layer is 0.001 mm to 1 mm.

[0020] The aforementioned proofing material contains an aqueous film-forming substance in its removable layer. This substance can undergo thermal dissociation under specific conditions, resulting in a significant reduction in adhesion and allowing the removable layer to be removed. When this proofing material is used for proofing printing, the base layer can be reused after removing the removable layer, thereby significantly reducing the proofing costs for printing companies. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the hierarchical structure of a proofing material according to one embodiment. Detailed Implementation

[0022] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is considered to be "connected" or "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "upper," "lower," "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0024] It should be noted that the degree adjectives such as "minimum," "moderate," and "sufficient" used in this article are for relative description only and do not represent absolute quantitative standards. Specifically: "minimum" refers to the implementation method with the minimum necessary degree while meeting basic functional requirements; "moderate" refers to a moderate and representative degree of implementation under conventional implementation conditions; and "sufficient" refers to an implementation degree that fully meets or exceeds the expected effect under optimal implementation conditions. The specific degree of implementation for these terms can be appropriately adjusted according to the actual application scenario, technical conditions, and design requirements. The degree description terms used in this article do not constitute a limitation on the scope of protection, nor should they be construed as the sole limitation on the degree of implementation of the technical solution.

[0025] The following section provides a more detailed explanation of the proofreading materials, in conjunction with the accompanying drawings and specific embodiments.

[0026] Please see Figure 1 One embodiment of the proofing material includes a base layer 10 and a movable layer 20 stacked together.

[0027] The substrate 10 is used to support the movable layer 20. Typically, the substrate 10 has a high procurement cost but also a high reusability. When the procurement cost of the substrate 10 exceeds the removal and installation costs of the movable layer 20, it becomes economical as the substrate 10.

[0028] Optionally, the substrate 10 material includes, but is not limited to: paper, polymer sheet, metal sheet or composite material.

[0029] In this embodiment, the base layer 10 is paper, which is often used as a substrate for packaging boxes and brochures.

[0030] Alternatively, the paper may be coated paper, white cardstock, grey cardstock, gold cardstock, or silver cardstock.

[0031] Preferably, the paper has a basis weight of 150 g / m² or greater.

[0032] Preferably, when the base layer 10 is paper, a first protective material is provided on the first surface of the base layer 10 near the removable layer 20. The first protective material is used to protect the first surface of the base layer 10. On the one hand, it can prevent moisture from entering the base layer 10 through the first surface; on the other hand, it can prevent the removal tool from damaging the first surface during the subsequent removal of the removable layer 20, thereby extending the service life of the base layer 10.

[0033] Optionally, the first protective material includes, but is not limited to: water-based varnish, UV varnish, polymer film, aluminum foil, and aluminum-plastic composite film.

[0034] Preferably, a second protective material is provided on the second surface of the base layer 10 away from the movable layer 20. By providing the second protective material, water vapor can be prevented from entering the base layer 10 through the second surface, thereby preventing the base layer 10 from deforming due to water absorption, thus protecting the base layer 10 and extending its service life.

[0035] Optionally, the second protective material includes, but is not limited to: water-based varnish, UV varnish, paraffin wax, polymer film, aluminum foil, and aluminum-plastic composite film.

[0036] Preferably, a third protective material is provided on the four cross-sections of the substrate layer 10. By providing the third protective material, water vapor is prevented from entering the substrate layer 10 through the four cross-sections, thereby significantly extending the service life of the substrate layer 10. The third protective material can be applied by coating or spraying.

[0037] Optionally, the third protective material includes, but is not limited to, UV varnish, paraffin wax, or other waterproof coatings.

[0038] In another embodiment, the base layer 10 is a polymer sheet. Polymer sheets have a higher procurement cost and are often used as substrates for cosmetic packaging boxes.

[0039] Alternatively, the polymer sheets include, but are not limited to: PP sheets, PET sheets, PS sheets, PE sheets, OPS sheets and PVC sheets.

[0040] In another embodiment, the substrate 10 is a metal sheet. Metal sheets have high procurement costs and are often used as substrates for container packaging or ointment packaging.

[0041] Optionally, the metal sheet includes, but is not limited to, tinplate sheet, aluminum sheet, copper sheet and stainless steel sheet.

[0042] In another embodiment, the base layer 10 is an aluminum-plastic composite material. Aluminum-plastic composite materials have high procurement costs and are widely used in pharmaceutical inner packaging materials, food packaging and daily chemical packaging.

[0043] Optionally, composite materials include, but are not limited to, paper-plastic composites, aluminum-plastic composites, and composites between different polymer materials.

[0044] It should be understood that the base layer 10 can be in sheet form or roll form, both of which are common forms of printing materials.

[0045] A movable layer 20 is stacked on the substrate layer 10. The movable layer 20 is obtained by drying water-based coatings or water-based inks. The water-based coatings or water-based inks contain water-based film-forming substances. During the drying process, the water-based film-forming substances undergo physical fusion or chemical cross-linking to form a dense movable layer 20, thus the movable layer 20 can be firmly adhered to the surface of the substrate layer 10. However, under certain conditions, the water-based film-forming substances that have undergone physical fusion or chemical cross-linking can undergo thermal dissociation. After thermal dissociation, the molecular weight of the water-based film-forming substances decreases significantly, and the adhesion is greatly reduced, making the movable layer 20 removable.

[0046] Thermal dissociation further includes two forms: thermal swelling dissociation and thermal cracking dissociation.

[0047] In this embodiment, the specific environment is a wet heating environment, and the thermal dissociation is thermal swelling dissociation, which is manifested as the water-based film-forming material with a three-dimensional network structure swelling or even dissolving in a high-temperature liquid under a wet heating environment.

[0048] Specifically, during the drying and film-forming process, on the one hand, the hydrophobic groups (such as long-chain alkyl groups and fluorine / silicon modified groups) in the aqueous film-forming material are tightly arranged after the water evaporates, forming a dense cross-linked network structure. This structure can effectively block water penetration. On the other hand, the aqueous film-forming material contains a small number of hydrophilic groups (such as carboxylic acid groups and hydroxyl groups), but these hydrophilic groups are wrapped by hydrophobic segments or fixed through cross-linking reactions during the film-forming process, and cannot fully contact water molecules. Therefore, the mobile layer 20 exhibits strong water resistance at room temperature.

[0049] Surprisingly, experiments have shown that some aqueous film-forming substances that have undergone physical fusion or chemical cross-linking can undergo thermal swelling and dissociation under wet heating conditions. This is because: (1) High temperature will activate and destroy the cross-linked structure of aqueous film-forming substances. Specifically, the energy provided by the wet heating environment can destroy secondary forces such as hydrogen bonds and van der Waals forces between molecules of aqueous film-forming substances, leading to the loosening of the cross-linked network. If the aqueous film-forming substance contains heat-sensitive groups, such as ester groups and ether bonds, the wet heating environment may also trigger the breaking of chemical bonds, causing the membrane structure to collapse. (2) Exposure and swelling of hydrophilic groups. In a wet heating environment, the movement of aqueous film-forming material chains intensifies, and the previously encapsulated hydrophilic groups are re-exposed, forming hydrogen bonds with water molecules. This triggers thermal swelling and dissociation of the movable layer 20. When the thermal swelling and dissociation is at a moderate limit, the movable layer 20 softens and its adhesion is significantly reduced. When the thermal swelling and dissociation is at a full limit, the movable layer 20 becomes colloidal. When the degree of swelling exceeds the tolerance limit of the crosslinked network, the movable layer 20 may even gradually dissolve in hot water. Therefore, the movable layer 20 that has undergone thermal swelling and dissociation can be removed by scraping or by dissolving it directly.

[0050] It should be noted that thermo-induced swelling dissociation only causes the hydrogen bonds of the molecules of the aqueous film-forming substance to break. Therefore, thermo-induced swelling dissociation is partially reversible. When the water dries, the removable layer 20 can restore the film structure, but the adhesion will be greatly reduced, so it can be removed.

[0051] Alternatively, the aqueous film-forming material may include, but is not limited to: polyurethane resins, acrylic resins, polyvinyl alcohol and its modified resins, polyoxyethylene resins, starch and its derivatives, polyvinylpyrrolidone, and environmentally responsive block copolymers.

[0052] Furthermore, aqueous film-forming substances containing ester groups include, but are not limited to: polyurethane resins, acrylic resins, polyvinyl alcohol and its modified resins, starch and its derivatives. Aqueous film-forming substances containing ether bonds include, but are not limited to: polyurethane resins, polyvinyl alcohol and its modified resins, polyethylene oxide resins, starch and its derivatives.

[0053] All of the above-mentioned aqueous film-forming substances can be obtained through market purchases.

[0054] Furthermore, the water-based coating is a water-based varnish, water-based varnish, or water-based ink. Water-based varnishes, water-based varnishes, and water-based inks typically use polyurethane resin or acrylic resin as the water-based film-forming substance, and therefore can be directly used to prepare the movable layer 20.

[0055] Optionally, wet heating can be water bath heating, steam heating, or liquid film heating.

[0056] Preferably, the wet heating is steam heating, which can cause moderate thermal swelling and dissociation of the movable layer 20 within 2-4 seconds, thereby allowing the movable layer 20 to be efficiently removed by scraping.

[0057] In another embodiment, the specific environment is a dry heating environment, and the thermally induced dissociation is thermally induced cracking dissociation. The internal manifestation is that the molecular chain of the aqueous film-forming material breaks under the action of internal stress, resulting in a significant reduction in molecular weight. The external manifestation is that the movable layer 20 has a large number of micropores, a significant volume expansion, and a significant reduction in adhesion, so it can be removed by external force.

[0058] Specifically, the movable layer 20 contains a foaming material. During the process of heating and foaming, the foaming material generates internal stress within the movable layer 20. Under the action of internal stress, the three-dimensional network molecular structure of the aqueous film-forming substance breaks down, which greatly reduces the molecular weight of the aqueous film-forming substance and significantly reduces the adhesion, thereby allowing the movable layer 20 to be removed from the base layer 10.

[0059] The foamed material contains a heat-sensitive component. When the ambient temperature is higher than the induction temperature of the heat-sensitive component, the heat-sensitive component can release a large amount of gas through decomposition, evaporation or sublimation. The gas directly or indirectly generates internal stress in the movable layer 20. The internal stress can cause the molecular chains of the aqueous film-forming material in the movable layer 20 to break, the molecular weight to decrease significantly, and a large number of pores to be generated in the movable layer 20, causing volume expansion. This significantly reduces the adhesion between the movable layer 20 and the substrate layer 10, thereby allowing the movable layer 20 to be removed from the substrate layer 10.

[0060] It should be noted that thermally induced decomposition causes the chemical bonds in the molecules of aqueous film-forming substances to break, therefore, thermally induced decomposition is irreversible.

[0061] In some embodiments, the foamed material is in granular form. During the release of gas by the heat-sensitive component, the generated gas causes the volume of the foamed material particles to expand, and the internal stress is indirectly provided by the outer surface of the foamed material particles. In other embodiments, the foamed material is dissolved and dispersed in the substrate layer 10, and the internal stress is directly provided by the released gas molecules.

[0062] Optionally, foamed materials can be classified as: physical foamed materials, chemical foamed materials, inorganic foamed materials, environmentally friendly foamed materials, and composite foamed materials.

[0063] Specifically, physically foamed materials include, but are not limited to: volatile liquids, compressed gases, supercritical fluids, foamed microspheres, expanded graphite, vermiculite powder, and expanded hexagonal boron nitride.

[0064] Optionally, the volatile liquid foaming material includes, but is not limited to: pentane (C5H 12 ), butane (C4H) 10 ), dichloromethane (CH2Cl2), HFC-134a. Compressed gas foaming materials include, but are not limited to: nitrogen (N2), carbon dioxide (CO2), and air. Supercritical fluid foaming materials include, but are not limited to: supercritical carbon dioxide (scCO2), supercritical nitrogen (scN2), and supercritical argon (scAr).

[0065] Chemical foaming materials include, but are not limited to: azo foaming materials, sulfonyl hydrazine foaming materials, carbonate foaming materials, hydrazine / acyl hydrazine foaming materials, hydrazine / acyl hydrazine foaming materials, and reactive foaming materials.

[0066] Specifically, azo-based foaming materials include, but are not limited to: azodicarbonamide (AC), azobisisobutyronitrile (AIBN), barium azodicarboxylate (BAB), and azodicarbonate (ADC). Sulfonyl hydrazine-based foaming materials include, but are not limited to: p-toluenesulfonyl hydrazine (TSH), benzenesulfonyl hydrazine (BSH), and diphenyl sulfone-3,3'-disulfonyl hydrazine (DPSH). Carbonate-based foaming materials include, but are not limited to: sodium bicarbonate (NaHCO3), ammonium bicarbonate (NH4HCO3), and ammonium carbonate ((NH4)2CO3). Nitro / nitroso-based foaming materials include, but are not limited to: nitrosopentamethylenetetramine (foaming material H), nitroguanidine (NG), and 2,2'-dinitrobenzene (DNB). Hydrazine / acyl hydrazine-based foaming materials include, but are not limited to: 4,4'-oxobisbenzenesulfonyl hydrazine (OBSH), trihydrazine triazine (THT), and 5-phenyltetrazole (5-PT). Reactive foaming materials include, but are not limited to: water (H2O, polyurethane), hydrogen peroxide (H2O2, rubber foam), and isocyanate self-reactive systems.

[0067] Inorganic foaming materials include, but are not limited to: carbonate foaming materials, metal hydride foaming materials, and silicate foaming materials.

[0068] Specifically, carbonate foaming materials include, but are not limited to: magnesium carbonate (MgCO3), calcium carbonate (CaCO3), and zinc carbonate (ZnCO3). Metal hydride foaming materials include, but are not limited to: aluminum hydride (AlH3), magnesium hydride (MgH2), and sodium borohydride (NaBH4). Silicate foaming materials include, but are not limited to: water glass (Na2SiO3) and bentonite.

[0069] Environmentally friendly foaming materials include, but are not limited to: bio-based foaming materials, HFOs foaming materials, and natural product foaming materials.

[0070] Specifically, bio-based foaming materials include, but are not limited to: polylactic acid (PLA) microspheres, starch-based granules, and cellulose foaming materials. HFOs foaming materials include, but are not limited to: HFO-1234ze, HFO-1336mzz, and HFO-1233zd. Natural product foaming materials include, but are not limited to: coconut oil derivatives and soybean oil-based polyols.

[0071] Composite foaming materials include, but are not limited to: endothermic-exothermic composite foaming materials, acid-base reactive foaming materials, and metal-organic composite foaming materials.

[0072] Specifically, endothermic-exothermic composite foaming materials include, but are not limited to: sodium bicarbonate and azodicarbonamide, citric acid and sodium bicarbonate. Acid-base reactive foaming materials include, but are not limited to: calcium carbonate and stearic acid, zinc oxide and stearic acid. Metal-organic composite foaming materials include, but are not limited to: aluminum hydride and polysiloxane, magnesium carbonate and azo compounds.

[0073] In one embodiment, the foaming material is foamed microspheres, which have a core-shell structure consisting of a polymer shell and a foaming agent core. When the temperature exceeds the induction temperature of the foaming agent core, the polymer shell softens, and the foaming agent core releases a large amount of gas. Under the pressure of the core, the volume of the foamed microspheres expands rapidly, thereby generating indirect internal stress within the movable layer 20 through the shell, causing thermally induced rupture and disintegration of the movable layer 20. The foamed microspheres are hollow spheres after foaming.

[0074] In another embodiment, the foaming material is expanded graphite. Graphite molecules have a parallel hierarchical structure, and the molecules between the layers are bound together by van der Waals forces. Expanded graphite is expanded by inserting an expanding agent between the layer molecules. When the ambient temperature is higher than the induction temperature of the expanding agent, the expanding agent decomposes and releases a large amount of gas. The pressure generated by the gas pushes the graphite molecules between the layers to expand violently along the axial direction, thereby generating internal stress within the movable layer 20 and causing thermally induced cracking and dissociation of the movable layer 20. The expanded graphite after expansion has a popcorn-like appearance.

[0075] It should be understood that when the foaming material is expanded graphite, since expanded graphite is black in appearance, the removable layer 20 is gray or black. Before proofreading, a base color layer can be set on the surface of the removable layer 20 so that the proofreading material has the correct color.

[0076] In another embodiment, the foaming material is modified sodium bicarbonate. The modified sodium bicarbonate particles are coated with a hydrophobic layer. When the ambient temperature is higher than the induction temperature of 60°C, the modified sodium bicarbonate particles can decompose to generate a large amount of carbon dioxide gas, thereby generating internal stress in the movable layer 20 and causing thermally induced cracking and disintegration of the movable layer 20.

[0077] In another embodiment, the foaming material is azobisisobutyronitrile (AIBN). AIBN particles are insoluble in water and have an induction temperature of 90-115°C. When the ambient temperature is higher than the induction temperature, AIBN particles can decompose to generate a large amount of nitrogen gas, which can generate a large amount of gas in the movable layer 20, thereby generating internal stress in the movable layer 20 and causing thermally induced cracking and disintegration of the movable layer 20.

[0078] In another embodiment, the foaming material is p-toluenesulfonyl hydrazine, which is insoluble in water. Its initiation temperature is 110-130°C. When the ambient temperature is higher than the initiation temperature, the p-toluenesulfonyl hydrazine particles can decompose to generate a large amount of nitrogen gas, and can generate a large amount of gas in the movable layer 20, thereby generating internal stress in the movable layer 20 and causing thermal cracking and disintegration of the movable layer 20.

[0079] In another embodiment, the foaming material is 4,4'-oxobis(benzenesulfonyl)hydrazine (OBSH). OBSH particles are insoluble in water, and their initiation temperature is 150-160°C. When the ambient temperature is higher than the initiation temperature, the OBSH particles decompose to generate a large amount of nitrogen and water vapor, which can produce a large amount of gas within the movable layer 20. This generates internal stress within the movable layer 20, causing thermally induced cracking and dissociation. OBSH particles are widely used in TPU and shoe material foaming processes. Notably, the water vapor generated during OBSH foaming can induce thermal swelling and dissociation of the aqueous film-forming material; this dual dissociation helps to facilitate the removal of the movable layer 20.

[0080] In another embodiment, the foaming material is azodicarbonamide, which is insoluble in water and has an induction temperature of 195-210°C. When the ambient temperature is higher than the induction temperature, the azodicarbonamide particles can decompose to generate a large amount of nitrogen and carbon monoxide, and can generate a large amount of gas in the movable layer 20, thereby generating internal stress in the movable layer 20 and causing thermal cracking and disintegration of the movable layer 20.

[0081] In another embodiment, the foaming material is a mixed foaming material, comprising a first foaming material and a second foaming material. The first foaming material has a first induction temperature, and the second foaming material has a second induction temperature, which is higher than the first induction temperature. When the ambient temperature is higher than the first induction temperature, the first foaming material foams, creating pores in the removable layer 20 while maintaining high adhesion, allowing ordinary offset printing ink to penetrate and dry in the removable layer 20 without causing it to peel off during printing. When the ambient temperature is higher than the second induction temperature, the second foaming material foams, significantly reducing the adhesion of the removable layer 20, thus allowing it to be removed.

[0082] Optionally, the particle size of the foaming material is 1 micrometer to 50 micrometers. Water-based coatings can be prepared using foaming materials with particle sizes within this range, and can be applied by offset printing, gravure printing, screen printing, or coating methods.

[0083] Optionally, the induction temperature of the foaming material is 60℃-200℃. This range of induction temperatures is relatively low, and the substrate layer 10 is not easily deformed during induction.

[0084] Preferably, the initiation temperature of the foaming material is 70℃-130℃. On the one hand, when the substrate 10 material is paper, this temperature can control the degree of deformation of the substrate 10 within a low range. On the other hand, it can prevent the foaming material from starting to foam during high-temperature anti-adhesion testing.

[0085] Optionally, dry heating environments include, but are not limited to: infrared heating, heat pressing, ultrasonic heating, and plasma heating.

[0086] However, it should be noted that during the dry heating process, temperature has both positive and negative effects on the adhesion of the movable layer 20: On the one hand, high temperature promotes the full cross-linking and curing of the aqueous film-forming material in the movable layer 20, forming a dense three-dimensional network structure, thereby enhancing the adhesion of the movable layer 20 to a certain extent; on the other hand, the foaming material is tightly wrapped by the highly cross-linked aqueous film-forming material in the movable layer 20, and the foaming of the foaming material will generate internal stress within the movable layer 20, which will produce two possible results:

[0087] (1) When the high-temperature strengthening effect is greater than the internal stress destructive effect, the internal stress has a limited impact on the hierarchical structure of the movable layer 20. Therefore, the movable layer 20 will still maintain a high adhesive strength. Experiments have shown that in a dry heating environment, when the ambient temperature is higher than 130℃, the high-temperature strengthening effect is greater than the internal stress destructive effect, and the movable layer 20 still maintains a high adhesive strength. Although the movable layer 20 can be removed, the removal is difficult.

[0088] (2) When the high-temperature strengthening effect is less than the internal stress destructive effect, the internal stress will directly destroy the hierarchical structure of the movable layer 20, causing the molecular chains of the aqueous film-forming material in the movable layer 20 to break, the molecular weight to decrease significantly, and a large number of pores to be generated in the movable layer 20. This significantly reduces the adhesion between the movable layer 20 and the substrate layer 10, but the movable layer 20 still maintains the integrity of the hierarchical structure. At this time, although the movable layer 20 can be removed, the removal efficiency is low. Experiments have shown that under dry heating conditions, when the ambient temperature is below 130℃, the high-temperature strengthening effect is less than the internal stress destructive effect.

[0089] It should be noted that, in order to maintain the adhesion of the foaming process, the existing technology usually adopts a dry heating method, namely heat pressing, to heat the foamed coating. On the one hand, the heat pressing temperature is usually higher than 130°C, and the high temperature strengthening effect is less than the internal stress damage effect. Therefore, the foamed coating can maintain a high adhesion. On the other hand, the pressure applied by the heat pressing plate can suppress the degree of thermal cracking and disintegration of the foamed coating, thereby ensuring that the foamed coating has a high adhesion.

[0090] In another preferred embodiment, the specific environment is a wet heating environment, and thermal dissociation includes both thermal swelling dissociation and thermal cracking dissociation.

[0091] Specifically, the movable layer 20 is obtained by coating with a water-based coating, which contains water-based film-forming substances and foaming materials. When the movable layer 20 is heated by a wet process, both thermal swelling and thermal cracking dissociation effects can be produced simultaneously.

[0092] Optionally, wet heating can be any one of water bath heating, steam heating, and liquid film heating.

[0093] Preferably, the wet heating method is steam heating, which can produce the following beneficial effects:

[0094] (1) When high-temperature steam acts on the movable layer 20, condensation occurs, releasing a large amount of heat. This causes the temperature of the movable layer 20 to reach 120℃-150℃ in a very short time. This temperature is exactly within the optimal foaming temperature range for most foaming materials. This temperature can cause the foaming material to generate ultimate internal stress and cause the movable layer 20 to undergo sufficient thermal rupture and dissociation. In addition, when the foaming material is foamed microspheres, the condensed water droplets can also protect the foamed microspheres, preventing the microsphere shell material from melting due to excessive temperature. It should be noted that after the proofing material has completed the proofing and printing, an image layer is set above the movable layer 20. Especially when the image layer is a solid color block, the image layer will prevent water vapor from contacting the movable layer 20. However, thermal rupture and dissociation can cause the rigid image layer to generate a large number of pores along with the movable layer 20, thereby creating conditions for water vapor to enter the movable layer 20 and trigger thermal swelling and dissociation.

[0095] (2) The limited high-temperature steam provided by the steam heating environment can enter the interior of the movable layer 20 through the pores. The high-temperature steam can undergo thermal swelling and dissociation with the aqueous film-forming material in the movable layer 20. Thermal swelling and dissociation can destroy the original hydrogen bonds between the molecules of the aqueous film-forming material and combine with water molecules to form new hydrogen bonds. This causes the molecular chains of the aqueous film-forming material with a three-dimensional network structure to break, and the molecular weight is greatly reduced. Externally, this means that while the movable layer 20 maintains its hierarchical structure, the adhesion, rigidity, and strength of the movable layer 20 are greatly reduced. The significant reduction in the adhesion, rigidity, and strength of the movable layer 20 helps to further enhance the effect of thermal cracking and dissociation. By controlling the heating time, the degree of thermal dissociation can be controlled. When the thermal swelling dissociation is at the moderate limit and the thermal cracking dissociation is at the full thermal cracking dissociation, the movable layer 20 will eventually disintegrate into powder polymerized by low adhesion under the synergistic effect of the dual dissociation. The powder polymerized by low adhesion can be easily removed by scraping or adsorption, thereby greatly enhancing the removal efficiency of the movable layer 20.

[0096] It is worth noting that when the steam heating time is excessive, the liquid water produced by the condensation of steam continues to increase, and therefore the movable layer can also undergo sufficient thermal swelling and dissociation. Therefore, the ideal steam heating time is 2-4 seconds.

[0097] It should be noted that the disintegration phenomenon generated by moderate thermal swelling and disintegration and full thermal rupture is something that cannot be achieved by dry heating, nor by other forms of wet heating, and is something that existing foaming processes need to avoid as much as possible.

[0098] (3) Steam heating has fast heat conduction and short time consumption, and can significantly reduce the deformation of the substrate layer 10. Comparative experiments show that in order to cause moderate thermal dissociation of the movable layer 20, steam heating takes 2-4 seconds, water bath heating takes 3-5 seconds, hot pressing heating takes 6-8 seconds, and infrared heating takes 30-120 seconds.

[0099] (4) The movable layer 20 obtained by steam heating has a high moisture content and is polymerized together with low adhesion. Therefore, dust pollution will not be generated during the cleaning operation.

[0100] (5) Steam heating does not produce wastewater and is environmentally friendly.

[0101] In another embodiment, the specific environment includes a dry heating environment and a wet heating environment, and the thermal dissociation includes two forms: thermally induced cracking dissociation and thermally induced swelling dissociation.

[0102] Specifically, firstly, dry heating is used to foam the foaming material in the removable layer 20. The internal stress generated by the foaming material causes thermal rupture and dissociation of the removable layer 20. This thermal rupture and dissociation reduces the molecular weight of the film-forming substance, decreases the adhesion, and creates numerous pores in the removable layer 20, while maintaining the integrity of its hierarchical structure. After proofing and printing, wet heating is used to cause thermal swelling and dissociation of the film-forming substance in the removable layer 20, thereby significantly reducing the adhesion of the removable layer 20. It is worth noting that the chemical bonds in the film-forming substance break during the thermal rupture and dissociation process, and this process is irreversible.

[0103] Preferably, the thermally induced cracking dissociation is a minimal thermally induced cracking dissociation. Minimal thermally induced cracking dissociation allows the movable layer 20 to maintain strong adhesion while generating a large number of pores, thereby preventing powder shedding from the movable layer 20 during the printing process due to low adhesion, which would affect the printing quality.

[0104] Specifically, the degree of thermally induced decomposition can be controlled by adjusting the temperature and time of dry heating, thereby controlling the size and number of pores.

[0105] It should be noted that during the dry heating process, the upper limit of the temperature needs to be controlled to prevent the aqueous film-forming material in the movable layer 20 from undergoing full cross-linking and curing due to high temperature.

[0106] Preferably, the dry heating method is infrared heating, and the heating temperature is 70℃-130℃.

[0107] Preferably, the wet heating is steam heating, and the thermal swelling dissociation is moderate thermal swelling dissociation.

[0108] One possible application scenario for this embodiment is as follows: In the field of conventional offset printing, the drying methods for conventional offset printing inks are penetration drying and oxidative film-forming drying. After the removable layer 20 undergoes minimal thermal rupture and dissociation through dry heating, a large number of micropores will be generated in the removable layer 20. These micropores can create conditions for the penetration drying of conventional offset printing inks. After the printing process is completed, the removable layer 20 can be easily removed by simply wet heating the printed sheet to cause moderate thermal swelling and dissociation of the removable layer 20.

[0109] Optionally, the thickness of the removable layer 20 is 0.001mm-1mm, and the removable layer 20 of the above thickness can be achieved by offset printing, gravure printing, flexographic printing, screen printing, coating or spraying.

[0110] Preferably, the thickness of the movable layer 20 is 0.01mm-0.1mm. When foamed microspheres are provided in the movable layer 20, the particle size of most foamed materials falls within this range. This thickness is just enough to cover the foamed material, giving the movable layer 20 a smooth surface. Furthermore, by limiting the thickness of the movable layer 20, the overall thickness of the proofing material is made as close as possible to the thickness of the base layer 10, thereby reducing the pressure difference between proofing printing and actual printing, and thus reducing dot deformation caused by the pressure difference.

[0111] Optionally, the thickness of the movable layer 20 is greater than or equal to 0.1 mm. When the specific environment is a dry heating environment, the movable layer 20 is more difficult to remove. By limiting the thickness of the movable layer 20, the force it bears during the removal process can be increased, thereby improving the removal effect of the movable layer 20.

[0112] It should be understood that in this invention, the removable layer 20 is a coating on which printing ink can be applied and which ultimately needs to be removed from the base layer 10. Therefore, the thinner the coating, the better it is to reduce material costs, provided that the coating is removable.

[0113] In another embodiment, the movable layer 20 is also provided with an adsorbent material. By adding the adsorbent material, the adsorption of the movable layer 20 can be increased, which is beneficial to improving the penetration drying and oxidative film drying effect of the movable layer 20 on the ink during proofing and printing.

[0114] Optionally, the adsorbent material includes, but is not limited to, zeolite powder, titanium dioxide, and silica powder.

[0115] The aforementioned proofing material contains an aqueous film-forming substance in its removable layer 20. This aqueous film-forming substance can undergo thermal dissociation under specific conditions. After thermal dissociation, the adhesive strength is significantly reduced, and the removable layer 20 can be removed. When the aforementioned proofing material is used for proofing printing, the base layer 10 can be reused after removing the removable layer 20, thereby significantly reducing the proofing costs for printing companies.

[0116] It should be noted that the descriptive terms such as "minimum," "moderate," and "sufficient" used in this specification are relative classifications based on the implementation gradient of the technical solution and do not constitute absolute quantitative standards. These classifications can be made using the following technical indicators:

[0117] (1) "Minimum" refers to the minimum necessary degree of implementation to achieve the basic function of the technical solution. For example, when the aqueous film-forming substance undergoes minimum thermal swelling and dissociation, the water content of the movable layer is 5% to 40% (excluding); when the aqueous film-forming substance undergoes minimum thermal cracking and dissociation, the volume of the foaming material in the movable layer increases by 5% to 40% (excluding).

[0118] (2) "Moderate limit" refers to the typical degree in the conventional implementation conditions in this field, such as when the aqueous film-forming material undergoes moderate thermal swelling and dissociation, the water content of the movable layer is 40% to 80% (excluding); when the aqueous film-forming material undergoes moderate thermal cracking and dissociation, the volume of the foaming material in the movable layer increases by 40% to 80% (excluding).

[0119] (3) “Sufficient” refers to the degree to which the optimal implementation effect is achieved or exceeded. For example, when the aqueous film-forming substance undergoes sufficient thermal swelling and dissociation, the water content of the movable layer reaches more than 80%; when the aqueous film-forming substance undergoes sufficient thermal rupture and dissociation, the volume of the foaming material in the movable layer increases by more than 80%.

[0120] The following are specific examples.

[0121] Example 1

[0122] This embodiment provides a proofing material; please refer to [link / reference]. Figure 1 The proofing material includes a base layer 10 and a removable layer 20 stacked together. The base layer 10 is a PVC sheet, and the removable layer 20 is obtained by drying a water-based varnish.

[0123] The aforementioned proofing material contains an aqueous film-forming substance in its removable layer 20. This substance undergoes thermal swelling and dissociation under a water bath heating environment. After this thermal swelling and dissociation, the removable layer 20 becomes colloidal, significantly reducing its adhesive strength. Therefore, the removable layer 20 can be scraped off. When this proofing material is used for plate proofing printing, the base layer 10 can be reused after removing the removable layer 20, thereby significantly reducing the plate proofing costs for printing companies.

[0124] Example 2

[0125] This embodiment provides a proofing material; please refer to [link / reference]. Figure 1 The proofing material includes a base layer 10 and a removable layer 20 stacked together. The base layer 10 is a paper sheet with a PP film protective layer on it. The removable layer 20 contains an oil-based and a water-based film-forming substance and a foaming material, wherein the foaming material is expanded graphite.

[0126] The aforementioned proofing material, the removable layer 20 contains expanded graphite foam, with an expanding agent inserted between the molecules of the expanded graphite layers. When the ambient temperature is higher than the induction temperature of the expanding agent, the expanding agent decomposes and releases a large amount of gas. The pressure generated by the gas pushes the graphite molecules between the layers to expand violently along the axial direction, thereby generating internal stress in the removable layer 20. The internal stress can cause the removable layer 20 to undergo thermally induced cracking and dissociation. Specifically, the molecular chains of the aqueous film-forming substance break, the molecular weight decreases significantly, and a large number of pores are generated in the removable layer 20, causing volume expansion. This significantly reduces the adhesion between the removable layer 20 and the substrate layer 10, thereby allowing the removable layer 20 to be removed from the substrate layer 10.

[0127] Example 3

[0128] This embodiment provides a proofing material; please refer to [link / reference]. Figure 1 The printing material comprises a base layer 10 and a movable layer 20 stacked together. The base layer 10 is a tinplate sheet, and the movable layer 20 contains an aqueous film-forming substance and a foaming material. The aqueous film-forming substance is acrylic resin, and the foaming material is low-temperature foamed microspheres.

[0129] The aforementioned proofing material contains an aqueous film-forming substance, specifically an aqueous acrylic resin, in the removable layer 20, and also includes a low-temperature foaming material. When heated with steam, the removable layer 20 undergoes both fully thermally induced cracking and dissociation, as well as moderately thermally induced swelling and dissociation. Under the synergistic effect of these two dissociations, the removable layer 20 ultimately disintegrates into a powder polymerized with low adhesion. This powder can be easily removed by scraping or adsorption, thus greatly enhancing the removal efficiency of the removable layer 20.

[0130] Example 4

[0131] The proofing material provided in this embodiment is similar to the proofing material provided in Embodiment 3, except that the foaming material is azobisisobutyronitrile.

[0132] When the above-mentioned proofing material is heated by dry method, the azobisisobutyronitrile particles can decompose to generate a large amount of nitrogen gas. The internal stress generated by the nitrogen gas can cause the movable layer 20 to undergo thermal cracking and disintegration.

[0133] Example 5

[0134] The proofing material provided in this embodiment is similar to the proofing material provided in Embodiment 3, except that the foaming material is 4,4'-oxobis(benzenesulfonylhydrazine) (OBSH).

[0135] When the aforementioned proofing material is heated using a dry method, OBSH particles can decompose to generate a large amount of nitrogen and water vapor. The internal stress generated by the nitrogen and water vapor can cause the movable layer 20 to undergo thermally induced cracking and dissociation. At the same time, the water vapor generated by OBSH will trigger the thermally induced swelling and dissociation of the aqueous film-forming material. This dual dissociation helps to improve the removal efficiency of the movable layer 20.

[0136] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A proofreading material, characterized in that, include: The base layer is selected from any one of paper, polymer sheets, metal sheets, and composite materials; as well as A movable layer is stacked on the substrate layer. The movable layer contains an aqueous film-forming substance that can undergo thermal dissociation under specific conditions. After the aqueous film-forming substance undergoes thermal dissociation, the movable layer can be removed.

2. The proofreading material according to claim 1, characterized in that, The aqueous film-forming substance is selected from at least one of polyurethane resin, acrylic resin, polyvinyl alcohol and its modified resins, polyoxyethylene resin, starch and its derivatives, polyvinylpyrrolidone, and environmentally responsive block copolymers.

3. The proofreading material according to claim 1, characterized in that, The specific environment is a wet heating environment, and the thermally induced dissociation is thermally induced swelling dissociation.

4. The proofreading material according to claim 1, characterized in that, The movable layer comprises a foamed material.

5. The proofreading material according to claim 4, characterized in that, The specific environment is a dry heating environment, and the thermally induced dissociation is thermally induced fracture dissociation.

6. The proofreading material according to claim 4, characterized in that, The specific environment is a wet heating environment, and the thermal dissociation is thermal swelling dissociation and thermal cracking dissociation.

7. The proofreading material according to claim 6, characterized in that, The specific environment is a steam-heated environment, and the thermal dissociation is moderately thermally induced swelling dissociation and fully thermally induced rupture dissociation.

8. The proofreading material according to claim 4, characterized in that, The specific environment includes a dry heating environment and a wet heating environment, and the thermally induced dissociation includes low-limit thermally induced cracking dissociation and moderate-limit thermally induced swelling dissociation.

9. The proofreading material according to any one of claims 4-8, characterized in that, The foaming material is selected from at least one of physical foaming materials, chemical foaming materials, inorganic foaming materials, environmentally friendly foaming materials, and composite foaming materials.

10. The proofreading material according to claim 9, characterized in that, The physical foaming material is selected from any one of volatile liquids, compressed gases, supercritical fluids, foamed microspheres, expanded graphite, vermiculite powder, and expanded hexagonal boron nitride; the chemical foaming material is selected from any one of azo foaming materials, sulfonyl hydrazine foaming materials, carbonate foaming materials, hydrazine / acyl hydrazine foaming materials, hydrazine / acyl hydrazine foaming materials, and reactive foaming materials; the inorganic foaming material is selected from any one of carbonate foaming materials, metal hydride foaming materials, and silicate foaming materials; the environmentally friendly foaming material is selected from any one of bio-based foaming materials, HFOs foaming materials, and natural product foaming materials; the composite foaming material is selected from any one of endothermic-exothermic composite foaming materials, acid-base reactive foaming materials, and metal-organic composite foaming materials.

11. The proofreading material according to claim 9, characterized in that, The foaming material has a specific initiation temperature, which is 60℃-200℃.

12. The proofreading material according to claim 1, characterized in that, The thickness of the movable layer is 0.001mm-1mm.

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