Thermal transfer printing protection thermal transfer ribbon for thermal transfer printing outdoor signboard and printed matter

Abstract

The invention relates to a thermal transfer printing protection thermal transfer ribbon for a thermal transfer printing outdoor signboard and a printed matter, the thermal transfer printing protection thermal transfer ribbon comprises a base material layer, a protection layer and an auxiliary agent layer, and one side of the base material layer is sequentially provided with the protection layer and the auxiliary agent layer. The thermal transfer printing protection thermal transfer ribbon has good transparency and good adhesive force, and can greatly prolong the outdoor service time of an image product by being transferred on a base material with a pattern layer in a thermal transfer printing mode.

Description

Technical Field

[0001] The invention relates to the technical field of thermal transfer printing, and in particular to a thermal transfer protection carbon belt and a printed object used for thermal transfer printing of outdoor signboards. Background Art

[0002] Graphic products such as advertisements, traffic signs, flags, license plates, retail product labels, on-vehicle graphics, etc. are widely used. Depending on the use, these items are often exposed to harsh environmental conditions, including exposure to extreme temperature fluctuations, exposure to rain and sunlight, physical friction caused by contact with people or objects, chemical attack caused by cleaning fluids or solvents and other chemicals in the environment. Graphic prints used outdoors are subject to particularly harsh weather conditions, so they must be able to withstand these conditions.

[0003] There are many methods for producing graphic products. For example, they include screen printing, lithography and inkjet printing. A special method for producing graphic products is thermal transfer, which is to transfer the color layer from a first substrate, i.e., a carrier film (usually a plastic film), to a second substrate, i.e., a target surface. The thermal transfer method forms an image by selectively transferring only the color layer portion of the first substrate to the second substrate. One advantage of the thermal transfer method is that the color layer can be made like a uniform sheet, without a latent image, and the pattern of the image depends on the control of the application process used. This makes it possible to produce a variety of customized image printing using a limited number of carrier films. At the same time, the carbon ribbon itself does not contain volatile substances such as solvents, and the thermal transfer printing process can basically achieve zero VOC emissions. In the thermal transfer process, the thermal transfer composition should be easily transferred from the carrier to the target surface. This method can be simplified by using a thermal transfer composition, for example, which softens at low temperatures and can be easily transferred by heating. Additionally, the thermal transfer composition should be capable of transferring cleanly, producing sharp edges along the perimeter of the image lines: the use of such a composition enables precision transfers with greater definition and finer detail.

[0004] For outdoor pattern products, the thermal transfer composition should have good durability and be able to withstand temperature fluctuations and exposure to other related environmental influences. Unfortunately, the thermal transfer composition that is commonly used and melted or softened at low temperatures has poor durability when exposed to high temperatures during use. In recent years, many carbon ribbons designed for outdoor use have been designed by using resins with good weather resistance such as PMMA as the main resin. They can also obtain good weather resistance outdoors. In order to further improve their weather resistance, a protective layer is usually covered on the surface of the pattern to further improve the weather resistance. The general practice is to protect the coloring layer by laminating or spraying a protective layer. The operation process is relatively complicated or solvents may evaporate during use. In view of this, the present invention provides a thermal transfer protective carbon ribbon and printed matter for thermal transfer outdoor signboards. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a thermal transfer protective carbon belt and printed matter for thermal transfer outdoor signboards.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] In a first aspect, a thermal transfer protective carbon ribbon for thermal transfer outdoor signage, the thermal transfer protective carbon ribbon comprising a substrate layer, a protective layer and an auxiliary agent layer, wherein the protective layer and the auxiliary agent layer are sequentially arranged on one side of the substrate layer;

[0008] The protective layer comprises the following raw materials: polyacrylate resin I and polyacrylate resin II; the polyacrylate resin I is mainly obtained by polymerizing a main monomer and a flexible monomer; the polyacrylate resin II is mainly obtained by polymerizing the main monomer; the molecular weight of the polyacrylate resin I is higher than that of the polyacrylate resin II;

[0009] The auxiliary agent layer comprises the following raw materials: a light stabilizer, a light absorber and an adhesive resin; the adhesive resin is mainly obtained by polymerizing the main monomer.

[0010] The beneficial effects of the present invention are as follows: the thermal transfer protective carbon tape of the present invention is composed of a protective layer and an auxiliary agent layer sequentially stacked on one side of the substrate film. The protective layer is mainly composed of a high molecular weight polyacrylate resin I, which itself has excellent weather resistance and ethanol and gasoline resistance, and is located above the auxiliary agent layer, which can effectively prevent the lower auxiliary agent layer from migrating to the surface, thereby causing the auxiliary agent to fail quickly and the image product to appear turbid; the auxiliary agent layer is composed of an adhesive resin, a light stabilizer and a light absorber, and the adhesive resin and the auxiliary agent have good compatibility, which greatly reduces the turbidity phenomenon that occurs when the auxiliary agent is used outdoors under extreme conditions or is soaked in solvents such as ethanol and gasoline in the presence of a large amount of auxiliary agents. Good adhesion to the substrate and improvement of the weather resistance of the pattern are achieved, greatly extending the service life of the image product. At the same time, by using it in conjunction with a color carbon ribbon, the pattern and the protective coating can be formed in one step, greatly reducing the process flow and saving costs.

[0011] Based on the above technical solution, the present invention can also be improved as follows.

[0012] Further, the main monomer includes at least one of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, 2-hydroxyethyl acrylate, 2-propyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acrylic acid, glycidyl methacrylate, methacrylic acid, acrylonitrile, acrylamide, cyclohexyl methacrylate, isobornyl methacrylate, and dimethylaminoethyl methacrylate; and / or

[0013] The flexible monomer comprises at least one of lauryl methacrylate, n-octyl methacrylate, acrylic acid, and methacrylic acid; and / or

[0014] The molar content of the main monomer in the polyacrylate resin I is 70%-90%, and the molar content of the flexible monomer in the polyacrylate resin I is 10%-30%; and / or

[0015] The molecular weight (Mn) of the polyacrylate resin I is 100,000-1,000,000. Taking into account the solvent resistance, transfer performance and transfer resolution, Mn is preferably 150,000-450,000. The glass transition temperature (Tg) of the polyacrylate resin I is 85° C.-150° C. Taking into account the foil holding performance and solvent resistance, Tg is preferably 100° C.-140° C.; and / or

[0016] The molecular weight of the polyacrylate resin II is Mn=10000-100000, preferably Mn=20000-60000, and the glass transition temperature of the polyacrylate resin II is 85°C-130°C, preferably Tg=100°C-120°C.

[0017] Further, the light stabilizer comprises a hindered amine light stabilizer, the melting point of the light stabilizer is above 60° C., and the molecular weight of the light stabilizer is above 1000; and / or

[0018] The light absorber is at least one of a benzotriazole-based light absorber and a triazine-based light absorber, the melting point of the light absorber is above 60° C., and the light absorber molecular weight of the light absorber is above 600; and / or

[0019] The molecular weight of the adhesive resin is 10,000-150,000, and the glass transition temperature of the adhesive resin is 50° C.-120° C.

[0020] Furthermore, the mass ratio of the polyacrylate resin I to the polyacrylate resin II in the protective layer is 85-97:3-15, and more preferably 90-95:5-10; and / or

[0021] The light stabilizer in the auxiliary agent layer accounts for 10%-30% of the total mass of the auxiliary agent layer, the light absorber in the auxiliary agent layer accounts for 10%-30% of the total mass of the auxiliary agent layer, and the adhesive resin in the auxiliary agent layer accounts for 40%-80% of the total mass of the auxiliary agent layer.

[0022] Furthermore, the thickness of the protective layer is 1.0 μm-5.0 μm, and more preferably 1.5 μm-3 μm; the thickness of the auxiliary agent layer is 0.5 μm-2 μm, and more preferably 0.8 μm-1.5 μm.

[0023] Furthermore, the raw materials of the protective layer also include a scratch-resistant additive; the scratch-resistant additive in the protective layer includes at least one of a slippery resin, micron-sized particles, and submicron-sized particles; the scratch-resistant additive accounts for 0.5%-10% of the total mass of the protective layer, and more preferably 0.5%-3%.

[0024] Furthermore, the thermal transfer protective carbon ribbon further comprises a release layer, and the release layer is arranged between the substrate layer and the protective layer;

[0025] The raw materials of the release layer include release layer resin and scratch-resistant additive; the release layer resin is polyacrylate resin I, and the scratch-resistant additive includes at least one of a slippery resin, micron-sized particles, and submicron-sized particles; the scratch-resistant additive accounts for 1%-10% of the mass of the release layer resin, preferably 3-5%; the thickness of the release layer is 0.2μm-1.0μm, and more preferably 0.3μm-0.6μm.

[0026] A further beneficial effect of the present invention is that the release layer uses acrylic resin as the main resin and introduces a scratch-resistant additive, thereby achieving good peeling performance and good scratch resistance of the thermal transfer carbon ribbon, while ensuring that the protective layer can achieve more precise and clear printing.

[0027] Furthermore, the glass transition temperature of the release layer resin is 65°C-130°C, and considering the foil holding performance and solvent resistance, preferably Tg=80°C-120°C. The molecular weight of the release layer resin is 10000-400000, and considering the solvent resistance, transfer performance and transfer resolution, preferably Mn=30000-150000.

[0028] Furthermore, the thermal transfer protective carbon tape further comprises an adhesive layer, and the adhesive layer is arranged on the surface of the auxiliary agent layer away from the substrate layer;

[0029] The raw materials of the bonding layer include bonding layer main resin and auxiliary resin;

[0030] The main resin of the bonding layer is a polyacrylate resin I, the molecular weight of the main resin of the bonding layer is 10000-100000, more preferably Mn=30000-60000, and the glass transition temperature of the main resin of the bonding layer is 50°C-120°C, more preferably 60°C-110°C acrylic resin;

[0031] The auxiliary resin is at least one of polyurethane resin and polyvinyl chloride-vinyl acetate resin; the auxiliary resin accounts for 10%-30% of the mass of the main resin of the bonding layer, and more preferably 15%-30%; the thickness of the bonding layer is 0.5μm-2μm, and more preferably 0.8μm-1.5μm.

[0032] A further beneficial effect of the present invention is that the adhesive layer is composed of acrylic resin and polyurethane resin (TPU), etc., which has good fluidity after being heated, ensuring good adhesion on substrates such as PMMA and PVC and when the substrate is uneven due to local attachment of a pattern layer, ensuring that the protective layer will not have bubbles falling off during use.

[0033] In a second aspect, a printed object is provided, wherein the printed object is obtained by transferring the thermal transfer protective carbon ribbon for thermal transfer outdoor signboards onto a pattern layer by thermal transfer.

[0034] The beneficial effects of the present invention are that the image product of the present invention has good outdoor durability, abrasion resistance and clear images. The terms "durable" and "durable" used herein refer to properties such as resistance to solvents and chemicals, resistance to ultraviolet light, resistance to abrasion, the ability to maintain the bonding between the thermal transfer layer and the printing base plate, and the ability to maintain the color gloss. The terms "weatherproof" and "weather resistance" refer to properties such as the ability to maintain the gloss, resistance to dust accumulation, and resistance to yellowing, all of which are under normal outdoor use conditions, where sunlight, temperature, humidity, etc. can affect the performance of the image. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of the thermal transfer protective carbon ribbon of the present invention. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0037] This embodiment relates to a thermal transfer protective carbon ribbon for thermal transfer outdoor signage, the thermal transfer protective carbon ribbon comprising a substrate layer, a protective layer and an auxiliary agent layer, one side of the substrate layer is sequentially provided with the protective layer and the auxiliary agent layer ( Figure 1 ). In addition, a back coating layer is provided on the other side of the substrate layer.

[0038] Regarding the above-mentioned substrate layer, back coating layer, protective layer and auxiliary agent layer, the preferred scheme of this embodiment is as follows.

[0039] (1) Base material

[0040] The substrate is a transparent flexible plastic film, such as polypropylene (PP), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene (PE), polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), etc. Among them, PET and PEN are preferred.

[0041] The thickness of the substrate is 4 μm-25 μm, preferably 4 μm-10 μm.

[0042] (2) Back coating

[0043] A layer provided to prevent adverse effects such as stickiness or wrinkles caused by heating from the back side of the substrate (the side of the substrate where the protective layer is not provided) during thermal transfer.

[0044] The resin of the back layer has no particular restrictions, and can be acrylic resin, cellulose resin, fluorocarbon resin, silicone resin (polyurethane modified silicone resin, acrylic modified silicone resin), polycarbonate resin, polyvinyl acetal resin and polyvinyl alcohol resin etc. The back layer can preferably carry out the resin of crosslinking and curing with a crosslinking agent. The crosslinking agent can be polyisocyanates etc. The back layer contains lubricant, particle etc. In the back layer containing lubricant, particle etc., the sliding property of this back layer is good.

[0045] Specifically, the lubricant can be silicone oil, polyethylene wax, paraffin, higher fatty acid ester (glycerol dioleate), higher fatty amide, higher fatty alcohol, organopolysiloxane, zinc stearate, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant, fluorine-based surfactant, organic carboxylic acid and its derivatives, and metal soap, etc.

[0046] Specifically, the particles may be organic particles, inorganic particles, etc. Organic particles: fluorine particles, acrylic particles, nylon particles, PTFE (polytetrafluoroethylene) particles, styrene particles, nylon particles, etc. Inorganic particles: silica, oxidized and talc, etc.

[0047] The thickness of the back coating is 0.1 μm-1.2 μm

[0048] The preparation method of the back coating layer is: dissolving the above polymer material into water or a corresponding solvent to prepare a coating, and then coating it on the side of the substrate surface away from the front layer by gravure coating or slit coating and drying. Release layer.

[0049] (3) Protective layer

[0050] In order to improve the barrier performance of the protective coating, that is, to prevent water and oxygen from contacting the coloring layer, thereby further improving the aging resistance of the coating. At the same time, to prevent the auxiliary agent layer / adhesive layer auxiliary agent from migrating upward, a transparent protective layer is specially set on the release layer of the protective carbon tape. As a transparent protective layer, this layer can be used alone or in combination with the release layer. The protective layer includes the following raw materials: polyacrylate resin I and polyacrylate resin II; the polyacrylate resin I is mainly obtained by polymerizing the main monomer and the flexible monomer; the polyacrylate resin II is mainly obtained by polymerizing the main monomer methyl methacrylate; the molecular weight of the polyacrylate resin I is higher than that of the polyacrylate resin II.

[0051] As the protective layer resin, thermoplastic resins may be selected, such as one or more of common resins such as polyacrylate resin I, polyvinyl chloride-vinyl acetate resin, polyurethane resin, cellulose resin, aldehyde ketone resin, phenolic resin, etc. In view of weather resistance and transparency, polyacrylate resin I is preferred.

[0052] Specifically, the main monomer includes at least one of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, 2-hydroxyethyl acrylate, 2-propyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acrylic acid, glycidyl methacrylate, methacrylic acid, acrylonitrile, acrylamide, cyclohexyl methacrylate, isobornyl methacrylate, and dimethylaminoethyl methacrylate. The flexible monomer includes at least one of lauryl methacrylate, n-octyl methacrylate, acrylic acid, and methacrylic acid.

[0053] Specifically, considering factors such as foil holding performance, weather resistance, transparency and adhesion performance, it is preferred that the polyacrylate resin has methyl methacrylate or ethyl methacrylate as the main monomer.

[0054] Considering the hardness of the polyacrylate resin after film formation and the brittleness of the resin, and in order to ensure the barrier effect of the protective layer on water vapor and the effect of delaying the migration of the additive, the selected resin should not be too brittle and have a good film-forming effect. Therefore, the molar content of the main monomer in the polyacrylate resin I is preferably 70%-90%, and the molar content of the flexible monomer in the polyacrylate resin I is 10%-30%.

[0055] The molecular weight (Mn) of the polyacrylate resin I is 100000-1000000, and considering the solvent resistance, transfer performance and transfer resolution, Mn is preferably 150000-450000, and the glass transition temperature (Tg) of the polyacrylate resin I is 85°C-150°C, and considering the foil retention performance and solvent resistance, Tg is preferably 100°C-140°C; and / or the molecular weight of the polyacrylate resin II is Mn=10000-100000; preferably Mn=20000-60000, and the glass transition temperature of the polyacrylate resin II is 85°C-130°C, and preferably Tg=100°C-120°C.

[0056] The mass ratio of the polyacrylate resin I to the polyacrylate resin II in the protective layer is 85-97:3-15, and more preferably 90-95:5-10.

[0057] To further improve the foil holding performance of the protective layer, the protective layer may also contain polyurethane resin or polyvinyl chloride-vinyl acetate resin with excellent flexibility. The content of polyurethane or polyvinyl chloride-vinyl acetate resin in the protective layer accounts for 1-5% of the main resin mass ratio, and more preferably 2-4%.

[0058] To ensure the effect of the protective layer, the thickness of the protective layer is preferably 1.0 μm-5.0 μm, more preferably 1.5 μm-3 μm. The protective layer with this thickness has a good barrier effect and can effectively block the migration of the auxiliary agent and the migration of the upper layer of water vapor to the printing layer.

[0059] Note: The protective layer can be used alone. When used alone, the raw material of the protective layer also includes a scratch-resistant additive; the scratch-resistant additive in the protective layer includes at least one of a slippery resin, micron-sized particles, and submicron-sized particles. This can improve the scratch resistance of the release layer or the protective coating after transfer, as well as the solvent wiping resistance of the protective coating after transfer.

[0060] Specifically, the particulate materials include organic particles and inorganic particles. Examples of organic particles include polyethylene wax powder, candelilla wax, carnauba wax, polytetrafluoroethylene-modified polyethylene, montan wax, Fischer-Tropsch wax, and other common types. Examples of inorganic particles include aluminum particles, zirconium oxide particles, calcium carbonate particles, silicon dioxide particles, titanium oxide, zinc oxide particles, and other metal oxide particles.

[0061] To ensure the transparency of the protective layer, it is not advisable to add too much particulate material, as too much will easily reduce the transparency of the release layer, resulting in reduced transparency of the entire protective coating after printing. Preferably, the amount of slippery resin such as silicone or particulate material added is 0.5%-10% of the resin mass, and more preferably 0.5%-3%.

[0062] The protective layer can be formed by dispersing or dissolving the above-mentioned materials in water or a suitable solvent, applying the resulting coating solution on the surface of the substrate by conventional methods such as (for example) gravure coating, micro-gravure coating, comma coating, doctor blade coating, die coating, etc., and heating and drying, thereby forming a protective layer.

[0063] (4) Auxiliary agent layer

[0064] In order to better improve the weather resistance of the protective carbon tape and extend the service life of the pattern. An auxiliary agent layer mainly composed of a light stabilizer, a light absorber and an adhesive resin is arranged on the side of the front layer of the protective carbon tape away from the substrate, and the adhesive resin is mainly obtained by polymerization of the main monomer. The light stabilizer in the auxiliary agent layer accounts for 10%-30% of the total mass of the auxiliary agent layer, the light absorber in the auxiliary agent layer accounts for 10%-30% of the total mass of the auxiliary agent layer, and the adhesive resin in the auxiliary agent layer accounts for 40%-80% of the total mass of the auxiliary agent layer.

[0065] To ensure that the additive does not appear white frost or white turbidity under high additive content. At the same time, consider the adhesion to the printing layer. The selected resin should have good compatibility with the light stabilizer and light absorber, and have good adhesion to the acrylic resin surface or PVC resin surface. The preferred adhesive resin is acrylic resin.

[0066] Taking the above-mentioned properties into consideration, the selected main monomer preferably contains one or more of the following monomers. Examples are as follows: methyl methacrylate, isooctyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, tert-butyl acrylate, n-octyldecyl acrylate, glycidyl methacrylate, 1,4-butylene glycol diacrylate, benzyl methacrylate, isobornyl acrylate, etc. The preferred main monomer is methyl methacrylate, and the preferred content is 50%-70% of the mass of the acrylic resin. The preferred second monomer is isobornyl acrylate or tert-butyl cyclohexyl acrylate. The acrylic resin prepared by selecting these monomers has good compatibility with light stabilizers and light absorbers, and the coating additive prepared by them is evenly distributed in the resin, which is conducive to reducing the occurrence of white turbidity.

[0067] The molecular weight of the adhesive resin is Mn=10000-150000, more preferably Mn=60000-120000. The Tg is preferably 50°C-120°C, more preferably 60°C-110°C.

[0068] In order to ensure good adhesion of the auxiliary layer, the proportion of adhesive resin in the auxiliary layer should not be too low. Too low will affect the adhesion performance of the auxiliary layer, resulting in reduced adhesion to the substrate or affecting the interlayer adhesion between the protective carbon ribbons. It is preferred that the adhesive resin accounts for 50%-70% of the auxiliary layer by mass. The acrylic resin selected in the above range can ensure good fluidity during thermal transfer and ensure good adhesion during transfer.

[0069] As the light absorber, for example, the ultraviolet absorber is a substance in which an addition polymerizable double bond such as a vinyl group, an acryloyl group, a methacryloyl group, or an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, or the like is introduced into a non-reactive ultraviolet absorber such as a salicylate group, a benzophenone group, a benzotriazole group, a triazine group, a substituted acrylonitrile group, a nickel chelate group, or a hindered amine group.

[0070] Since the acrylic resin itself absorbs ultraviolet light below 300 nm, a light absorber that absorbs ultraviolet light well in the UV-A and UV-B bands is preferred. Examples thereof include hydroxyphenyl triazine compounds such as 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-s-triazine, 2-[2-hydroxy-4-(2-ethylhexyloxy)phenyl]-4,6-biphenyl-s-triazine, and 2-[[2-hydroxy-4-[1-(2-ethylhexyloxycarbonyl)ethoxy]phenyl]]-4,6-biphenyl-s-triazine; and benzotriazole ultraviolet absorbers such as 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol and 2-(5-chloro-2-benzotriazolyl)-6-tert-butyl-p-cresol.

[0071] To further prevent migration, the light absorber is preferably a solid substance at room temperature. For further optimization, a light absorber with a melting point above 60°C is preferred, and a melting point above 100°C is more preferred. At the same time, a large molecular weight can also effectively prevent migration, and the molecular weight of the light absorber is preferably above 600. To ensure good weather resistance and extend the service life of the substrate as much as possible, the amount of the light absorber is more than 10% of the mass ratio of the auxiliary agent layer and does not exceed 30%. Too high an amount will affect the film-forming properties of the auxiliary agent layer and reduce adhesion.

[0072] As the light stabilizer, a hindered amine light stabilizer is preferred, and examples thereof include hindered amine light stabilizers such as bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2'-n-butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate.

[0073] From the perspective of migration resistance, it is preferred that the light stabilizer has a melting point above 60°C and a molecular weight above 1000.

[0074] In order to further improve the adhesion performance of the auxiliary agent layer, the auxiliary agent layer may also contain polyurethane resin or polyvinyl chloride-vinyl acetate resin with excellent flexibility and adhesion performance.

[0075] The content of polyurethane or polyvinyl chloride-vinyl acetate resin in the auxiliary agent layer accounts for 3%-15% of the main resin by mass, and more preferably 5%-10%.

[0076] The thickness of the auxiliary agent layer is preferably 0.5 μm-2 μm, more preferably 0.8 μm-1.5 μm.

[0077] The auxiliary agent layer can be formed by dispersing or dissolving the above-mentioned materials in water or a suitable solvent, applying the resulting coating liquid on the surface of the substrate by conventional methods such as (for example) gravure coating, micro-gravure coating, comma coating, doctor blade coating, die coating, etc., and heating and drying, thereby forming the auxiliary agent layer.

[0078] In order to further improve the weather resistance, scratch resistance, pollution resistance, design and other functions of the front layer of the entire protective carbon ribbon and ensure that the front layer has a good peeling effect and better printing fineness, a release layer can be set on the side of the protective layer close to the substrate. The release layer will be printed on the substrate together with the protective layer during the printing process, which plays a role in adjusting the peeling force and further improving the performance of the front layer. In order to further ensure the adhesion of the protective carbon ribbon to the substrate, it is suitable for different substrates. An adhesive layer can be applied on the side away from the substrate above the auxiliary agent layer. The following is a description of the release layer and the adhesive layer.

[0079] (5) Release layer

[0080] The raw materials of the release layer include release layer resin and scratch-resistant additive; the release layer resin is polyacrylate resin I, and the scratch-resistant additive includes at least one of a slippery resin, micron-sized particles, and submicron-sized particles; the scratch-resistant additive accounts for 1%-10% of the mass of the release layer resin, preferably 3%-5%; the thickness of the release layer is 0.2μm-1.0μm, and more preferably 0.3μm-0.6μm.

[0081] As the release layer resin, thermoplastic resins may be selected, such as one or more of common resins such as polyacrylate resin, polyvinyl chloride-vinyl acetate resin, polyurethane resin, cellulose resin, aldehyde ketone resin, phenolic resin, etc. In view of weather resistance and transparency, polyacrylate resins are preferred.

[0082] Preferably, in view of factors such as peeling performance, foil holding performance, weather resistance, transparency and adhesion performance, the polyacrylate resin preferably uses methyl methacrylate or ethyl methacrylate as the main monomer, and should also be copolymerized with one or more flexible monomers such as lauryl methacrylate, n-octyl methacrylate, acrylic acid, methacrylic acid, etc.

[0083] The glass transition temperature of the release layer resin is 65°C-130°C. Considering the foil holding performance and solvent resistance, Tg is preferably 80°C-120°C. The molecular weight of the release layer resin is 10000-400000. Considering the solvent resistance, transfer performance and transfer resolution, Mn is preferably 30000-150000.

[0084] Furthermore, in order to improve the scratch resistance of the release layer or the protective coating after transfer, and the solvent wiping resistance of the protective coating after transfer, the release layer should contain a scratch resistance additive; the release layer resin is polyacrylate resin I, and the scratch resistance additive includes at least one of a slippery resin, a micron-sized particle material, and a submicron-sized particle material;

[0085] The granular materials include organic particles and inorganic particles. Examples of organic particles include common types such as polyethylene wax powder, candelilla wax, carnauba wax, polytetrafluoroethylene-modified polyethylene, montan wax, and Fischer-Tropsch wax.

[0086] Examples of the inorganic particles include aluminum particles, zirconium oxide particles, calcium carbonate particles, silicon dioxide particles, titanium oxide particles, zinc oxide particles and other metal oxide particles.

[0087] To ensure the transparency of the release layer, it is not advisable to add too much particulate material, as too much particulate material may easily reduce the transparency of the release layer and the transparency of the entire protective coating after printing. Preferably, the scratch-resistant additive accounts for 1%-10% of the mass of the release layer resin, preferably 3%-5%.

[0088] To further ensure the foil retention and flexibility of the release layer, polyurethane or polyvinyl chloride-vinyl acetate resin can be added to the release layer as the second resin in the release layer, and the added amount is 1%-10% of the mass of the main resin, preferably 3%-5%.

[0089] To ensure the effect of the release layer, the thickness of the release layer is preferably 0.2 μm-1.0 μm, and more preferably 0.3 μm-0.6 μm.

[0090] The release layer can be formed by dispersing or dissolving the above-mentioned materials in water or a suitable solvent, applying the resulting coating liquid on the surface of the substrate by conventional methods such as (for example) gravure coating, micro-gravure coating, comma coating, doctor blade coating, die coating, etc., and heating and drying, thereby forming a release layer.

[0091] (6) Adhesive layer

[0092] The main resin of the adhesive layer can be a polyacrylate resin as the first resin. Considering factors such as peeling performance, foil holding performance, weather resistance, transparency and adhesion performance, it is preferred that the polyacrylate resin has methyl methacrylate or ethyl methacrylate as the main monomer, and should also be copolymerized with one or more flexible monomers such as lauryl methacrylate, n-octyl methacrylate, acrylic acid, methacrylic acid, etc.

[0093] Furthermore, the main monomer is preferably methyl methacrylate, preferably in an amount of 40%-60% by mass of the acrylic resin, and the second monomer is preferably lauryl methacrylate or methacrylic acid. Such monomers are suitable for substrates and provide good adhesion to acrylic resins and PVC resins.

[0094] The molecular weight of the main resin of the bonding layer is 10000-100000, more preferably Mn=30000-60000, and the glass transition temperature of the main resin of the bonding layer is 50°C-120°C, more preferably 60°C-110°C acrylic resin;

[0095] In order to further improve the adhesion performance of the auxiliary agent layer, the auxiliary agent layer may also contain polyurethane resin or polyvinyl chloride-vinyl acetate resin with excellent flexibility and adhesion performance as auxiliary resin.

[0096] The auxiliary resin accounts for 10%-30% of the mass of the main resin of the bonding layer, and more preferably 15%-30%; the thickness of the bonding layer is 0.5μm-2μm, and more preferably 0.8μm-1.5μm. .

[0097] The bonding layer can be formed by dispersing or dissolving the above-mentioned materials in water or a suitable solvent, applying the resulting coating solution on the surface of the substrate by conventional methods such as (for example) gravure coating, micro-gravure coating, comma coating, doctor blade coating, die coating, etc., and heating and drying, thereby forming a bonding layer.

[0098] Finally, it should be noted that when preparing the protective layer, release layer, auxiliary agent layer, adhesive layer or back coating coating of the present invention, in addition to the above main materials, a small amount of auxiliary agents such as leveling agent and defoaming agent can be added as required.

[0099] As a method for transferring the transfer layer to the transfer body by the protective resin carbon ribbon for outdoor printing products described above, known methods such as hot stamping (foil pressing) based on thermal engraving, full-surface or strip transfer using a heat roller, and a thermal printer (sometimes also called a thermal transfer printer) using a thermal head (thermal print head) can be used.

[0100] In summary, the present invention prepares a protective carbon tape whose main resin is acrylic resin, which has good light transmittance and excellent weather resistance. By adjusting the interlayer structure and introducing a light absorber with good migration resistance, it is fully transferred to a substrate printed with a pattern by thermal transfer or precisely controlled to transfer only on the pattern layers, thereby achieving good adhesion to the substrate and improving the weather resistance of the pattern, greatly extending the service life of the image product. At the same time, by using a color carbon tape simultaneously, the pattern and the protective coating can be formed at one time, greatly reducing the process flow and saving costs. The following is a further explanation of the invention with specific embodiments and comparative examples.

[0101] Example 1

[0102] A method for preparing a thermal transfer protective carbon ribbon for thermal transfer outdoor signage (eg Figure 1 As shown), including: (each component is by weight)

[0103] Back coating liquid:

[0104] Mix 40 parts of 2-butanone, 35 parts of toluene, 10 parts of polyurethane modified silicone resin, 10 parts of acrylic modified silicone resin, 3 parts of zinc stearate, and 2 parts of glycerol dioleate to obtain a back coating liquid;

[0105] Release layer coating liquid:

[0106] 35 parts of 2-butanone, 45 parts of toluene, 10 parts of MB250 (Boriel Chemical), and 0.1 parts of KF-393 (BYK) were stirred and dissolved to obtain a release layer coating liquid;

[0107] Protective layer coating liquid:

[0108] 40 parts of 2-butanone, 49 parts of toluene, 1 part of BR83 (Mitsubishi), and 10 parts of MB250 (Bolier Chemical) were stirred and dissolved to obtain a protective layer coating solution;

[0109] Auxiliary agent coating liquid:

[0110] 25 parts of 2-butanone, 35 parts of toluene, 20 parts of M810 (Dow), 10 parts of UV absorber 460 (Qitai Technology), and 10 parts of light stabilizer 622LD (Qitai Technology) were stirred and dissolved to obtain an additive layer coating liquid;

[0111] A polyethylene terephthalate (PET) film with a thickness of 4.5 μm was used as a base material, a 60% corona was applied to one side of the base material, and a back coating liquid was applied to the corona side of the base material by gravure coating, so that the thickness after drying was 0.4 μm, thereby forming a back coating layer;

[0112] A release liquid is coated on the other side of the base material to form a release layer with a thickness of 0.5 μm after drying; a protective layer coating liquid is then coated on the release layer by gravure coating to form a protective layer with a thickness of 2.4 μm after drying; an auxiliary agent layer coating liquid is then coated on the protective layer by gravure coating to form an auxiliary agent layer with a thickness of 0.5 μm after drying, thereby obtaining a thermal transfer protective carbon ribbon for thermal transfer outdoor signboards.

[0113] Example 2

[0114] The difference between Example 2 and Example 1 is that the formula of the auxiliary agent layer coating liquid in Example 2 is as follows:

[0115] Auxiliary agent coating liquid:

[0116] Add 25 parts of 2-butanone, 35 parts of toluene, 15 parts of M810 (Dow), 15 parts of UV absorber 460 (Qiti Technology), and 10 parts of light stabilizer 622LD (Qiti Technology), stir and dissolve them evenly to obtain an auxiliary agent layer coating liquid.

[0117] Example 3

[0118] The difference between Example 3 and Example 1 is that the formula of the auxiliary agent layer coating liquid in Example 3 is as follows:

[0119] Auxiliary agent coating liquid:

[0120] Add 25 parts of 2-butanone, 35 parts of toluene, 30 parts of M810 (Dow), 5 parts of UV absorber 460 (Qiti Technology), and 5 parts of light stabilizer 622LD (Qiti Technology), stir and dissolve them evenly to obtain an auxiliary agent layer coating liquid.

[0121] Example 4

[0122] The difference between Example 4 and Example 1 is that the coating thickness of the auxiliary agent layer in Example 4 is increased to 1.0 μm.

[0123] Example 5

[0124] The difference between Example 5 and Example 1 is that an adhesive layer is introduced in Example 5.

[0125] Next coating liquid:

[0126] 35 parts of 2-butanone, 45 parts of toluene and 20 parts of BR113 (Mitsubishi) were stirred and dissolved and mixed uniformly to obtain a coating liquid for the adhesive layer;

[0127] Then, an adhesive liquid is coated on the protective layer by gravure coating to form an adhesive layer with a thickness of 0.4 μm after drying, thereby obtaining a thermal transfer protective carbon ribbon for thermal transfer outdoor signboards.

[0128] Example 6

[0129] The difference between Example 6 and Example 1 is that the formula of the release layer coating liquid in Example 6 is:

[0130] Release layer coating liquid:

[0131] 35 parts of 2-butanone, 45 parts of toluene, 10 parts of BR85 (Mitsubishi), 0.1 parts of KF-393 (Shin-Etsu Silicone), and 0.05 parts of KF-105 (Shin-Etsu Silicone) were stirred and dissolved and mixed uniformly to obtain a release layer coating liquid.

[0132] Example 7

[0133] The difference between Example 7 and Example 1 is that the formula of the release layer coating liquid in Example 7 is:

[0134] 35 parts of 2-butanone, 45 parts of toluene, 10 parts of MB250 (Bolier Chemical), and 0.5 parts of PEW-0674F (Tianshi wax powder) were stirred and dissolved and mixed uniformly to obtain a release layer coating liquid.

[0135] Example 8

[0136] The difference between Example 8 and Example 1 is that the thickness of the protective layer in Example 8 is adjusted to 1.5 μm.

[0137] Example 9

[0138] The difference between Example 9 and Example 1 is that the thickness of the protective layer in Example 9 is adjusted to 3.5 μm.

[0139] Example 10

[0140] The difference between Example 10 and Example 1 is that the formula of the protective layer coating liquid in Example 10 is:

[0141] Protective layer coating liquid:

[0142] 40 parts of 2-butanone, 49 parts of toluene, 1 part of BR83 (Mitsubishi), and 10 parts of MB11 (Boriel Chemical) were stirred and dissolved and mixed uniformly to obtain a protective layer coating liquid.

[0143] Embodiment 11

[0144] The difference between Example 11 and Example 1 is that the formula of the protective layer coating liquid in Example 11 is:

[0145] Protective layer coating liquid:

[0146] 40 parts of 2-butanone, 49 parts of toluene, 1 part of BR83 (Mitsubishi), and 10 parts of MB247 (Boriel Chemical) were stirred and dissolved and mixed uniformly to obtain a protective layer coating liquid.

[0147] Example 12

[0148] The difference between Example 12 and Example 1 is that there is no release layer in Example 12, and the formula of the protective layer coating liquid is:

[0149] Protective layer coating liquid:

[0150] 40 parts of 2-butanone, 49 parts of toluene, 1 part of BR83 (Mitsubishi), 10 parts of MB250 (Boriel Chemical), 0.1 part of KF-393 (Shin-Etsu Silicone), and 0.05 part of KF-105 (Shin-Etsu Silicone) were stirred and dissolved to obtain a protective layer coating liquid.

[0151] Comparative Example 1

[0152] The difference between Comparative Example 1 and Example 1 is that there is no release layer in Comparative Example 1, and the formula of the protective layer coating liquid is:

[0153] Protective layer coating liquid:

[0154] 40 parts of 2-butanone, 49 parts of toluene, 1 part of BR83 (Mitsubishi), and 10 parts of MB250 (Boriel Chemical) were stirred and dissolved and mixed uniformly to obtain a protective layer coating liquid.

[0155] Comparative Example 2

[0156] The difference from Example 5 is that there is no auxiliary agent layer in Comparative Example 2.

[0157] Comparative Example 3

[0158] The difference between Comparative Example 1 and Example 1 is that there is no protective layer in Comparative Example 1.

[0159] Comparative Example 4

[0160] The difference between Comparative Example 1 and Example 1 is that the formula of the protective layer coating liquid in Comparative Example 1 is:

[0161] Protective layer coating liquid:

[0162] 40 parts of 2-butanone, 48 parts of toluene and 10 parts of BR83 (Mitsubishi) were stirred and dissolved and mixed uniformly to obtain a protective layer coating.

[0163] Test example

[0164] Print sample preparation: Use the traffic printer DTP-1300 to transfer the company's self-developed high weather-resistant red ribbon (the main resin component is acrylic resin) to the 3MⅤ class reflective film, and then transfer the protective layer carbon ribbon to the ink layer simultaneously.

[0165] (1) Light transmittance

[0166] ① The light transmittance of the protective layer is measured by using a retroreflection test system to test the retroreflection coefficient of the protective layer before and after transfer (observation angle 0.2°, incident angle -4°), and the light transmittance is calculated by the following formula:

[0167]

[0168] ②Ultraviolet transmittance test method: refer to GB / T 17032~1997 Test method for ultraviolet transmittance of textiles and fabrics.

[0169] (2) Solvent resistance test

[0170] The solvent resistance test was carried out in accordance with the national standard "GB-T 23989-2009 Determination of Solvent Resistance to Wiping of Coatings" and ethanol and gasoline resistance tests were carried out.

[0171] (3) Adhesion test

[0172] The adhesion test is carried out in accordance with the national standard "GB / T 9286-2021 Scratch Test for Paints and Varnishes".

[0173] (4) Weather resistance evaluation

[0174] The weather resistance of the samples was evaluated by the following methods:

[0175] ① Refer to the xenon lamp aging conditions in the national standard "GB / T 18833-2012 Road Traffic Reflective Sheeting", use a xenon lamp aging test chamber to age for 4000 hours, and observe whether there are wrinkles, bubbles, cracks, etc. on the surface; and measure the color difference before and after accelerated aging.

[0176] ②High and low temperature test: Place the prepared sample in a high and low temperature box at -40℃ for 24 hours; after returning to room temperature, place it at 60℃ and 90% humidity for another 24 hours to observe the white frost on the surface.

[0177] In order to verify the inhibitory effect of the protective carbon ribbon on white frost, ethanol and gasoline were used for 1 hour immersion test and the surface conditions were observed.

[0178] Table 1 Performance test results of printed samples of Examples 1-4

[0179]

[0180] Table 2 Performance test results of printed samples of Examples 5-8

[0181]

[0182] Table 3 Performance test results of printed samples of Examples 9-12

[0183]

[0184]

[0185] Table 4 Performance test results of printed samples of Comparative Examples 1-4

[0186]

[0187] It can be seen from the above embodiments and comparative examples that the protective carbon tape prepared by the method of the present invention has high light transmittance and strong ultraviolet absorption ability, and has a good protective effect on the printed layer with patterns. The printed product using the protective carbon tape can have a maximum weather resistance of 4000 hours and can still meet the basic use requirements of the reflective film. At the same time, the designed layer structure has a good inhibitory effect on the phenomenon of failure caused by the migration of the light absorber and the problem of frosting. In addition, the prepared protective carbon tape has good adhesion on the PMMA substrate and excellent resistance to conventional solvents such as ethanol and gasoline.

[0188] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A thermal transfer protective carbon ribbon for thermal transfer outdoor signage, characterized in that: The thermal transfer protective carbon ribbon comprises a substrate layer, a protective layer and an auxiliary agent layer, wherein the protective layer and the auxiliary agent layer are sequentially arranged on one side of the substrate layer; The protective layer comprises the following raw materials: polyacrylate resin I and polyacrylate resin II; the polyacrylate resin I is mainly obtained by polymerizing a main monomer and a flexible monomer; the polyacrylate resin II is mainly obtained by polymerizing the main monomer; the molecular weight of the polyacrylate resin I is higher than that of the polyacrylate resin II; The auxiliary agent layer comprises the following raw materials: a light stabilizer, a light absorber and an adhesive resin; the adhesive resin is mainly obtained by polymerizing the main monomer.

2. The thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to claim 1, characterized in that: The main monomer includes at least one of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, 2-hydroxyethyl acrylate, 2-propyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acrylic acid, glycidyl methacrylate, methacrylic acid, acrylonitrile, acrylamide, cyclohexyl methacrylate, isobornyl methacrylate, and dimethylaminoethyl methacrylate; and / or The flexible monomer comprises at least one of lauryl methacrylate, n-octyl methacrylate, acrylic acid, and methacrylic acid; and / or The molar content of the main monomer in the polyacrylate resin I is 70%-90%, and the molar content of the flexible monomer in the polyacrylate resin I is 10%-30%; and / or The molecular weight of the polyacrylate resin I is 100,000-1,000,000, and the glass transition temperature of the polyacrylate resin I is 85° C.-150° C.; and / or The molecular weight of the polyacrylate resin II is 10,000-100,000, and the glass transition temperature of the polyacrylate resin II is 85° C.-130° C.

3. The thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to claim 1, characterized in that: The light stabilizer comprises a hindered amine light stabilizer; and / or The light absorber is at least one of a benzotriazole-based light absorber and a triazine-based light absorber; and / or The molecular weight of the adhesive resin is 10,000-150,000, and the glass transition temperature of the adhesive resin is 50° C.-120° C.

4. The thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to claim 1, characterized in that: The mass ratio of the polyacrylate resin I to the polyacrylate resin II in the protective layer is 85-97:3-15; and / or The light stabilizer in the auxiliary agent layer accounts for 10%-30% of the total mass of the auxiliary agent layer, the light absorber in the auxiliary agent layer accounts for 10%-30% of the total mass of the auxiliary agent layer, and the adhesive resin in the auxiliary agent layer accounts for 40%-80% of the total mass of the auxiliary agent layer.

5. The thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to claim 1, characterized in that: The thickness of the protective layer is 1.0 μm-5.0 μm; the thickness of the auxiliary agent layer is 0.5 μm-2 μm.

6. A thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to any one of claims 1 to 5, characterized in that: The raw materials of the protective layer also include a scratch-resistant additive; the scratch-resistant additive in the protective layer includes at least one of a slippery resin, micron-grade particles, and submicron-grade particles; the scratch-resistant additive accounts for 0.5%-10% of the total mass of the protective layer.

7. A thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to any one of claims 1 to 5, characterized in that: The thermal transfer protective carbon ribbon further comprises a release layer, wherein the release layer is arranged between the substrate layer and the protective layer; The raw materials of the release layer include release layer resin and scratch-resistant additive; the release layer resin is polyacrylate resin I; the scratch-resistant additive accounts for 1%-10% of the mass of the release layer resin; the thickness of the release layer is 0.2μm-1.0μm.

8. The thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to claim 7, characterized in that: The glass transition temperature of the release layer resin is 65° C.-130° C., and the molecular weight of the release layer resin is 10,000-400,000.

9. A thermal transfer protective carbon ribbon for thermal transfer outdoor signage according to any one of claims 1 to 5, characterized in that: The thermal transfer protective carbon ribbon further comprises an adhesive layer, and the adhesive layer is arranged on the surface of the auxiliary agent layer away from the substrate layer; The raw materials of the bonding layer include bonding layer main resin and auxiliary resin; The main resin of the bonding layer is polyacrylate resin I, the molecular weight of the main resin of the bonding layer is 10000-100000, and the glass transition temperature of the main resin of the bonding layer is 50°C-120°C; The auxiliary resin is at least one of polyurethane resin and polyvinyl chloride-vinyl acetate resin; the auxiliary resin accounts for 10%-30% of the mass of the main resin of the bonding layer; the thickness of the bonding layer is 0.5μm-2μm.

10. A printed matter, characterized in that: The printed matter is obtained by transferring the thermal transfer protective carbon ribbon for thermal transfer outdoor signboards as described in any one of claims 1 to 9 onto the pattern layer by thermal transfer.

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