Thermal transfer sheet for rub-resistant high resolution color patterns and method of making the same

Abstract

The present application relates to the field of heat transfer printing consumables, and relates to a heat transfer printing sheet for a high-resolution color pattern with friction resistance and a preparation method thereof, which comprises a back coating layer, a substrate and an ink layer sequentially attached from top to bottom, wherein the ink layer is composed of a yellow ink layer, a magenta ink layer and a cyan ink layer sequentially stacked from top to bottom; the ink layer is formed by coating an ink liquid, and the ink liquid is mainly composed of the following components: acrylic resin, polyurethane resin, pigment, filler and dispersant; the acrylic resin has an average molecular weight of 10000-50000 and a glass transition temperature of 65-150 DEG C. The heat transfer printing sheet can not only realize printing of a high-precision dot superimposed color pattern through three-color strips, but also make the transferred pattern have strong friction resistance by using polyurethane resin with an average molecular weight of 10000-50000 and a glass transition temperature of -30-0 DEG C.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat transfer printing consumables, in particular to a heat transfer printing sheet for a high-resolution color pattern with friction resistance and a preparation method thereof. BACKGROUND

[0002] Heat transfer printing refers to a printing method in which a ribbon with a transferable ink layer is heated by a thermal print head of a heat transfer printer, and the ink layer is transferred to a substrate. Resin ribbons have better printing quality and weather resistance than wax-based ribbons and mixed base ribbons.

[0003] The images formed by the heat melting transfer method have high concentration and high definition, so this method is suitable for printing of images such as text and barcodes. Currently, resin-based carbon ribbons on the market are mainly used for single-color printing or special-color printing of label printing, such as PP, PET, and copper plate paper stickers. However, color printing for outdoor advertising and packaging sleeves requires both high resolution and friction resistance. In view of this, the present application provides a heat transfer printing sheet for a high-resolution color pattern with friction resistance and a preparation method thereof. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a heat transfer printing sheet for a high-resolution color pattern with friction resistance and a preparation method thereof. The purpose is to use yellow, magenta, and cyan three-color superposition printing to more conveniently realize color-rich pattern printing, and to use a resin with good friction resistance in the ink layer to give the pattern strong friction resistance. Therefore, the heat transfer printing sheet can further fill the technical gap of color pattern printing by color printing of heat transfer resin ribbons.

[0005] The present application solves the above technical problems. The first aspect is to provide a heat transfer printing sheet for a high-resolution color pattern with friction resistance, which comprises a back coating layer, a substrate, and an ink layer sequentially attached from top to bottom. The ink layer is composed of a yellow ink layer, a magenta ink layer, and a cyan ink layer sequentially superimposed from top to bottom.

[0006] The ink layer is formed by coating an ink liquid. The ink liquid mainly consists of the following components: solvent, acrylic resin, polyurethane resin, pigment, filler, and dispersant. The average molecular weight of the acrylic resin is 10000-50000, and the glass transition temperature is 65-150℃.

[0007] The back coating layer is formed by coating a back coating liquid.

[0008] The principle of the present application is: in order to improve the completeness and clarity of image transfer, the acrylic resin with an average molecular weight of 10000-50000, preferably 20000-35000 is adopted, and too low or too high molecular weight may cause uneven distribution of the ink liquid coated on the surface of the substrate, and the above-mentioned molecular weight interval can take into account the transfer effect while reducing the problem of poor transfer caused by too high molecular weight of thermoplastic acrylic; in order to avoid the problem of tailing after the melting of the resin in the ink layer when the print head is heated, the acrylic resin with a glass transition temperature (TG) value of 65℃-150℃, preferably 80℃-110℃ is adopted, and a higher TG value can realize higher precision dot transfer; in order to improve the adhesion effect of the ink layer on the surface of the substrate after transfer, and improve the film forming property and flow property of the acrylic resin, the use of polyurethane resin can further improve the clarity of the image of the transferred body and reduce color deviation and pattern loss caused by transfer defects such as block and tailing; in order to help the ink layer separate from the substrate, the inorganic filler is added to the ink layer to facilitate the separation of the ink layer from the substrate.

[0009] The beneficial effects of the present application are: the thermal transfer sheet of the present application can not only realize high-precision dot superposition of color patterns through three color bands, but also use acrylic resin with an average molecular weight of 10000-50000 and polyurethane resin with a glass transition temperature of 65℃-150℃, so that the transferred pattern has strong rubbing resistance; the inorganic filler is added to the ink layer to facilitate the separation of the ink layer from the substrate.

[0010] On the basis of the above technical scheme, the present application can also be improved as follows.

[0011] Further, the polyurethane resin is a thermoplastic polyurethane resin, and the average molecular weight of the thermoplastic polyurethane resin is 8000-15000, and the glass transition temperature is-30℃-0℃.

[0012] The beneficial effects of the above further scheme are: in order to further improve the rubbing resistance of the transferred pattern and reduce transfer defects such as block and tailing, the polyurethane resin material in the ink layer adopts thermoplastic polyurethane resin and / or chloroethylene-vinyl acetate copolymer resin, preferably thermoplastic polyurethane resin with a molecular weight of 8000-15000, which can improve the flexibility of the thermal transfer sheet and the scratch resistance of the transferred pattern.

[0013] Further, the ink liquid includes yellow ink liquid, magenta ink liquid and cyan ink liquid, and the pigment includes yellow pigment, magenta pigment and cyan pigment.

[0014] The yellow ink layer is coated by the yellow ink liquid, and the yellow ink liquid is mainly mixed by the following components in parts by weight: solvent 90 parts, acrylic resin 30-40 parts, polyurethane resin 10-20 parts, yellow pigment 5-15 parts, filler 5-15 parts, and dispersant 0.3-1.5 parts;

[0015] The magenta ink layer is coated by the magenta ink liquid, and the magenta ink liquid is mainly mixed by the following components in parts by weight: solvent 90 parts, acrylic resin 30-40 parts, polyurethane resin 10-20 parts, magenta pigment 5-15 parts, filler 5-15 parts, and dispersant 0.3-1.5 parts;

[0016] The cyan ink layer is coated by the cyan ink liquid, and the cyan ink liquid is mainly mixed by the following components in parts by weight: solvent 90 parts, acrylic resin 30-40 parts, polyurethane resin 10-20 parts, cyan pigment 5-15 parts, filler 5-15 parts, and dispersant 0.3-1.5 parts.

[0017] Further, the back coating liquid is mainly mixed by the following components in parts by weight: solvent 90 parts, polyurethane modified silicone resin 5-15 parts, acrylic modified silicone resin 5-15 parts, polyvinyl acetal resin 20-40 parts, and polyvinyl butyral resin 20-40 parts.

[0018] Further, the yellow pigment is pigment yellow 14; the magenta pigment is pigment red 48:2; and the cyan pigment is pigment blue 15:4.

[0019] The beneficial effect of the above further scheme is that the above-mentioned pigments achieve good coloring effect.

[0020] Further, the filler is any one or a combination of at least two of talc, calcium carbonate, mica powder, barium sulfate, magnesium sulfate, and titanium dioxide; the dispersant is any one or a combination of at least two of inorganic dispersant, organic small molecule type dispersant, and high molecular type dispersant; and the solvent is any one or a combination of the two of 2-butanone and toluene. For example, the dispersant is an acrylic high molecular type dispersant, which can improve the uniformity and storage stability of the ink system, and facilitate mass production.

[0021] The beneficial effect of the above further scheme is that the filler can improve the peeling effect of the thermal transfer sheet during transfer, and at the same time, can improve the abrasion resistance of the transferred pattern by filling the surface of the base material; and the use of 2-butanone and / or toluene as the solvent can ensure the sufficient dispersion and mixing of the components in the back coating layer and the ink layer.

[0022] Further, the base body is any one of polypropylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene, polyvinyl alcohol, polymethyl methacrylate.

[0023] The beneficial effect of the above further scheme is that the various films used as the base body can better ensure that the back coating layer and the ink layer can be effectively coated on the surface of the base body.

[0024] Further, the thickness of the base body is 2-15 μm; the thickness of the back coating layer is 0.2-1.0 μm; the thickness of the yellow ink layer in the ink layer is 0.8-2 μm, the thickness of the magenta ink layer is 0.8-2 μm, and the thickness of the cyan ink layer is 0.8-2 μm.

[0025] The beneficial effect of the above further scheme is that within this thickness range, the adhesion of the thermal transfer sheet to the substrate can be ensured, and the heat transfer efficiency of the print head can be ensured, and the ink layer can achieve accurate peeling.

[0026] The second aspect of the present application is to provide a preparation method of a thermal transfer sheet for a high-resolution color pattern resistant to friction, comprising the following steps:

[0027] S1: liquid preparation:

[0028] Back coating liquid: prepare a back coating liquid for standby;

[0029] Ink liquid: add acrylic resin and polyurethane resin to the solvent for dissolution, then add pigments, fillers and dispersants, stir and mix to prepare an ink liquid for standby;

[0030] S2: corona treatment;

[0031] A base body is provided, and the two surfaces of the base body are corona treated;

[0032] S3: coating;

[0033] The back coating liquid prepared in step S1 is coated on one surface of the base body in step S2, and then dried to form a back coating layer, which is ready for use;

[0034] The ink liquid prepared in step S1 is coated on the surface away from the back coating layer of the base body, and then dried to form an ink layer, thereby obtaining a thermal transfer sheet for a high-resolution color pattern resistant to friction.

[0035] The ink liquid in the step S1 comprises yellow ink liquid, magenta ink liquid and cyan ink liquid; acrylic resin and polyurethane resin are dissolved in solvent, and then corresponding pigments, fillers and dispersants are added, stirred and mixed to prepare the yellow ink liquid, the magenta ink liquid and the cyan ink liquid. The preparation of the ink layer in the step S3 comprises sequentially preparing the yellow ink layer, the magenta ink layer and the cyan ink layer; the yellow ink liquid, the magenta ink liquid and the cyan ink liquid are sequentially coated on the surface of the back coating layer away from the base, and then sequentially dried to form the yellow ink layer, the magenta ink layer and the cyan ink layer, which is the ink layer.

[0036] Further, in the step S3, the back coating liquid is coated by using a ceramic anilox roller with a precision of 200-250 lines, the coating speed is 60-100 m / min, the drying temperature is 50-100℃, and the drying time is 40-60 s; the ink liquid is coated by using a ceramic anilox roller with a precision of 200-250 lines, the coating speed is 60-100 m / min, the drying temperature is 40-100℃, and the drying time is 40-60 s.

[0037] The beneficial effects of the above scheme are that the thermal transfer sheet prepared by the above preparation method can greatly reduce the scratches caused by the thermal transfer sheet when transferring patterns on the smooth substrate surface, adapt to different substrates, and has low production cost and simple and feasible process. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The figure is a structural schematic diagram of the thermal transfer sheet for the friction-resistant high-resolution color pattern of the present application.

[0039] Figure 2 The figure is a sample diagram of the printing test of the present application.

[0040] In the drawings, the components represented by each reference numeral are listed as follows:

[0041] 1-back coating layer, 2-base, 3-ink layer. DETAILED DESCRIPTION

[0042] The principles and characteristics of the present application are described below, and the examples are only used to explain the present application, not to limit the scope of the present application.

[0043] Example 1:

[0044] The present embodiment provides a thermal transfer sheet for friction-resistant high-resolution color pattern (such as Figure 1 ), which comprises a back coating layer 1, a base 2 and an ink layer 3 sequentially attached from top to bottom, the ink layer 3 is composed of a yellow ink layer, a magenta ink layer and a cyan ink layer sequentially stacked from top to bottom.

[0045] The ink layer 3 is coated by an ink liquid, which is mainly composed of solvent, acrylic resin, polyurethane resin, pigment, filler and dispersant; the acrylic resin has an average molecular weight of 10000-50000 and a glass transition temperature of 65-150℃; the back coating layer 1 is coated by a back coating liquid.

[0046] Preferably, the polyurethane resin is a thermoplastic polyurethane resin, which has an average molecular weight of 8000-15000. The filler is any one of talcum powder, calcium carbonate, mica powder, barium sulfate, magnesium sulfate, titanium dioxide or a combination of at least two thereof; the dispersant is any one of inorganic dispersant, organic small molecule type dispersant, high molecular type dispersant or a combination of at least two thereof. The substrate 2 is any one of polypropylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene, polyvinyl alcohol, polymethyl methacrylate. The thickness of the substrate 2 is 2-15μm; the thickness of the back coating layer 1 is 0.2-1.0μm; the thickness of the yellow ink layer in the ink layer 3 is 0.8-2μm, the thickness of the magenta ink layer 3 is 0.8-2μm, and the thickness of the cyan ink layer is 0.8-2μm.

[0047] Specifically, the ink liquid includes yellow ink liquid, magenta ink liquid and cyan ink liquid, the pigment includes yellow pigment, magenta pigment and cyan pigment; the yellow ink layer is coated by the yellow ink liquid, 2-butanone 40 parts, toluene 40 parts, acrylic resin 20 parts, polyurethane resin 10 parts, yellow pigment 9 parts, filler 9 parts and dispersant 1 part; the coating thickness is 0.6μm; the magenta ink layer is coated by the magenta ink liquid, which is mainly composed of the following components in weight fraction: 2-butanone 40 parts, toluene 40 parts, acrylic resin 20 parts, polyurethane resin 10 parts, magenta pigment 9 parts, filler 9 parts and dispersant 1 part; the coating thickness is 0.6μm; the cyan ink layer is coated by the cyan ink liquid, which is mainly composed of the following components in weight fraction: 2-butanone 40 parts, toluene 40 parts, acrylic resin 20 parts, polyurethane resin 10 parts, cyan pigment 9 parts, filler 9 parts and dispersant 1 part; the coating thickness is 0.6μm.

[0048] The yellow pigment is pigment yellow 14; the magenta pigment is pigment red 48:2; the cyan pigment is pigment blue 15:4. The filler of the yellow ink liquid, the magenta ink liquid and the cyan ink liquid is talcum powder. The dispersant of the yellow ink liquid, the magenta ink liquid and the cyan ink liquid is acrylic high molecular type dispersant.

[0049] Specifically, the back coating liquid is mainly prepared by mixing the following components in parts by weight: 30 parts of 2-butanone, 30 parts of toluene, 10 parts of polyurethane modified silicone resin, 10 parts of acrylic modified silicone resin, 30 parts of polyvinyl acetal acetal-based resin, and 30 parts of polyvinyl butyral-based resin. The coating thickness is 1.0 μm.

[0050] Specifically, the base 2 is a polyethylene terephthalate film with a thickness of 4.5 μm.

[0051] The preparation method of the heat transfer sheet for high-resolution color pattern with friction resistance according to the present embodiment comprises the following steps:

[0052] S1: Preparation of liquid:

[0053] Back coating liquid: prepare a back coating liquid for standby;

[0054] Ink liquid: add acrylic resin and polyurethane resin to the solvent for dissolution, then add pigments, fillers and dispersants, and mix to prepare an ink liquid for standby;

[0055] S2: Corona treatment;

[0056] A base 2 is provided, and the surfaces of both sides of the base 2 are subjected to corona treatment;

[0057] S3: Coating;

[0058] The back coating liquid prepared in step S1 is coated on one surface of the base 2 in step S2, and then dried to form a back coating layer 1 for standby;

[0059] The ink liquid prepared in step S1 is coated on the surface of the back coating layer 1 away from the base 2, and then dried to form an ink layer 3, thereby obtaining a heat transfer sheet for high-resolution color pattern with friction resistance.

[0060] Specifically, the ink liquid in step S1 includes yellow ink liquid, magenta ink liquid and cyan ink liquid; the acrylic resin and polyurethane resin are added to the solvent for dissolution, and then the corresponding pigments, fillers and dispersants are added, and mixed to prepare the yellow ink liquid, magenta ink liquid and cyan ink liquid, respectively. The preparation of the ink layer 3 in step S3 includes sequentially preparing the yellow ink layer, magenta ink layer and cyan ink layer; the yellow ink liquid, magenta ink liquid and cyan ink liquid are sequentially coated on the surface of the back coating layer 1 away from the base 2, and then sequentially dried to form the yellow ink layer, magenta ink layer and cyan ink layer, which is the ink layer 3.

[0061] Specifically, in step S3, the back coating layer 1 is prepared by using a ceramic anilox roller with a precision of 230 lines to coat the back coating liquid at a speed of 60-100 m / min, and the drying temperature is 100°C and the drying time is 60 s; the ink layer 3 is prepared by using a ceramic anilox roller with a precision of 230 lines to coat the ink liquid at a speed of 60-100 m / min, and the drying temperature is 60°C and the drying time is 60 s.

[0062] Example 2

[0063] The difference between this example and Example 1 is that:

[0064] The yellow ink layer is prepared by coating the following yellow ink liquid: 45 parts of toluene, 45 parts of methyl ketone, 40 parts of acrylic resin (average molecular weight of 20000-35000, Tg of 65°C), 10 parts of polyurethane resin (average molecular weight of 8000-15000), 9 parts of yellow pigment, 9 parts of filler, and 1 part of dispersant, and the coating thickness is 1 μm.

[0065] The yellow ink layer is prepared by coating the following yellow ink liquid: 45 parts of toluene, 45 parts of methyl ketone, 40 parts of acrylic resin (average molecular weight of 20000-35000, Tg of 65°C), 10 parts of polyurethane resin (average molecular weight of 8000-15000), 9 parts of yellow pigment, 9 parts of filler, and 1 part of dispersant, and the coating thickness is 1 μm.

[0066] The yellow ink layer is prepared by coating the following yellow ink liquid: 45 parts of toluene, 45 parts of methyl ketone, 40 parts of acrylic resin (average molecular weight of 20000-35000, Tg of 65°C), 10 parts of polyurethane resin (average molecular weight of 8000-15000), 9 parts of yellow pigment, 9 parts of filler, and 1 part of dispersant, and the coating thickness is 1 μm.

[0067] Example 3

[0068] The difference between this example and Example 1 is that:

[0069] The yellow ink layer is prepared by coating the following yellow ink liquid: 45 parts of toluene, 45 parts of methyl ketone, 40 parts of acrylic resin (average molecular weight of 20000-35000, Tg of 65°C), 10 parts of polyurethane resin (average molecular weight of 8000-15000), 9 parts of yellow pigment, 9 parts of filler, and 1 part of dispersant, and the coating thickness is 1 μm.

[0070] The magenta ink layer is coated from a magenta ink liquid in the following proportions by weight: toluene 45 parts, methyl ketone 45 parts, acrylic resin 40 parts (average molecular weight 20,000-35,000, Tg 85°C), polyurethane resin 20 parts (average molecular weight 8,000-15,000), magenta pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 1.2 μm.

[0071] The cyan ink layer is coated from a cyan ink liquid in the following proportions by weight: toluene 45 parts, methyl ketone 45 parts, acrylic resin 40 parts (average molecular weight 20,000-35,000, Tg 85°C), polyurethane resin 20 parts (average molecular weight 8,000-15,000), cyan pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 1.2 μm. The rest is the same as in Example 1.

[0072] Example 4:

[0073] The difference between this example and Example 1 is that:

[0074] The yellow ink layer is coated from a yellow ink liquid in the following proportions by weight: toluene 45 parts, methyl ketone 45 parts, acrylic resin 30 parts (average molecular weight 20,000-35,000, Tg 105°C), polyurethane resin 20 parts, yellow pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 1.5 μm.

[0075] The magenta ink layer is coated from a magenta ink liquid in the following proportions by weight: toluene 45 parts, methyl ketone 45 parts, acrylic resin 30 parts (average molecular weight 20,000-35,000, Tg 105°C), polyurethane resin 20 parts, magenta pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 1.5 μm.

[0076] The cyan ink layer is coated from a cyan ink liquid in the following proportions by weight: toluene 45 parts, methyl ketone 45 parts, acrylic resin 30 parts (average molecular weight 20,000-35,000, Tg 105°C), polyurethane resin 20 parts (average molecular weight 8,000-15,000), cyan pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 1.5 μm. The rest is the same as in Example 1.

[0077] Example 5:

[0078] The difference between this example and Example 1 is that:

[0079] The yellow ink layer is coated from a yellow ink liquid having the following weight parts: toluene 45 parts, methyl ethyl ketone 45 parts, acrylic resin 25 parts (average molecular weight 20,000-35,000, Tg 85°C), polyurethane resin 25 parts (average molecular weight 8,000-15,000), yellow pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 2.5 μm.

[0080] The magenta ink layer is coated from a magenta ink liquid having the following weight parts: toluene 45 parts, methyl ethyl ketone 45 parts, acrylic resin 25 parts (average molecular weight 20,000-35,000, Tg 85°C), polyurethane resin 25 parts (average molecular weight 8,000-15,000), magenta pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 2.5 μm.

[0081] The cyan ink layer is coated from a cyan ink liquid having the following weight parts: toluene 45 parts, methyl ethyl ketone 45 parts, acrylic resin 25 parts (average molecular weight 20,000-35,000, Tg 85°C), polyurethane resin 25 parts (average molecular weight 8,000-15,000), cyan pigment 9 parts, filler 9 parts, dispersant 1 part, and the coating thickness is 2.5 μm. The rest is the same as in Example 1.

[0082] Comparative Example 1:

[0083] The same back coating liquid, coating thickness, coating method, and printing method as in Example 3 are used, but the resin of the ink liquid (including yellow ink liquid, magenta ink liquid, and cyan ink liquid) in ink layer 3 is replaced with a common polyester resin, i.e., the average molecular weight is not in the range of 8,000-15,000. The rest is the same as in Example 3.

[0084] Comparative Example 2:

[0085] The same back coating liquid, coating thickness, coating method, and printing method as in Example 3 are used, but the resin of the ink liquid (including yellow ink liquid, magenta ink liquid, and cyan ink liquid) in ink layer 3 is replaced with a vinyl chloride-vinyl acetate copolymer resin. The rest is the same as in Example 3.

[0086] Comparative Example 3:

[0087] The same back coating liquid, coating thickness, coating method, and printing method as in Example 3 are used, but the resin of the ink liquid (including yellow ink liquid, magenta ink liquid, and cyan ink liquid) in ink layer 3 is replaced with a vinyl chloride-vinyl isobutyl ether copolymer resin. The rest is the same as in Example 3.

[0088] Test Example:

[0089] Performance testing of the printed samples of Examples 1-5 and Comparative Examples 1-3.

[0090] Using a color marking printer (manufactured by Matan, model Sprinter 3), the heat transfer sheet prepared in the present examples and comparative examples was transferred onto copper plate paper to form an image (default print test pattern) as shown; the printing speed was set to 0.5 m / min, and the printing density of yellow, magenta and cyan was 23. Figure 2

[0091] The image formed was visually confirmed, and then evaluated according to the following evaluation criteria after 100 rubs with a 1000 g weight on a cloth cover:

[0092] A: No significant loss was observed in the image after rubbing;

[0093] B: Slight loss was observed in the image;

[0094] NG: A large amount of loss was observed in the image.

[0095] The results are shown in Tables 1 and 2. In Example 1, the coating thickness was slightly thin, resulting in color band adhesion during transfer, but the transferred pattern was not lost. In Example 5, the coating thickness was too high, resulting in reverse adhesion of the superimposed part in the superimposed dark color area, resulting in poor interlayer closeness, and a large amount of pattern loss during rubbing.

[0096] Table 1 Test results of Examples 1-5

[0097]

[0098] Table 2 Test results of Comparative Examples 1-3

[0099] Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Print Test B B NG

[0100] ​In summary, the above printing test results, by comparing examples 1-5 with comparative examples 1-2, adding acrylic resin in ink layer 3, and selecting acrylic resin with molecular weight of 20000-35000, too low or too high molecular weight may cause uneven distribution of coating liquid on the surface of the substrate, selecting acrylic resin with this molecular weight range can take into account the transfer effect, while reducing the problem of poor transfer and poor adhesion of the substrate surface caused by too high molecular weight; the TG value of the acrylic resin is 35-130°C, preferably 85-115°C, a higher TG value can avoid the problem of tailing after the resin is melted when the print head is heated, and can further improve the clarity of the image on the transferred body, reduce color deviation and pattern defects caused by transfer defects such as block and tailing; adding polyurethane resin with molecular weight of 8000-15000 in ink layer 3 can reduce the problem of tailing during thermal transfer, while improving the adhesion of the transferred pattern on the substrate surface. By comparing the results of examples 1-5 with comparative example 3, it is shown that ink layer 3 can improve the integrity of the transferred pattern.

[0101] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0102] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A heat transfer sheet for a friction-resistant high-resolution color pattern, characterized by, It comprises a back coating layer (1), a base (2) and an ink layer (3) which are sequentially attached from top to bottom, and the ink layer (3) is composed of yellow ink layer, magenta ink layer and cyan ink layer which are sequentially stacked from top to bottom; The ink layer (3) is coated by ink liquid, and the ink liquid is mainly composed of solvent, acrylic resin, polyurethane resin, pigment, filler and dispersant; the average molecular weight of the acrylic resin is 20000-35000, and the glass transition temperature is 65-150℃; The back coating layer (1) is coated by back coating liquid; The polyurethane resin is thermoplastic polyurethane resin, and the average molecular weight of the thermoplastic polyurethane resin is 8000-15000, and the glass transition temperature is-30-0℃; The ink liquid includes yellow ink liquid, magenta ink liquid and cyan ink liquid, and the pigment includes yellow pigment, magenta pigment and cyan pigment; The yellow ink layer is coated by the yellow ink liquid which is mainly composed of the following components by weight: solvent 90 parts, acrylic resin 30-40 parts, polyurethane resin 10-20 parts, yellow pigment 5-15 parts, filler 5-15 parts and dispersant 0.3-1.5 parts; The magenta ink layer is coated by the magenta ink liquid which is mainly composed of the following components by weight: solvent 90 parts, acrylic resin 30-40 parts, polyurethane resin 10-20 parts, magenta pigment 5-15 parts, filler 5-15 parts and dispersant 0.3-1.5 parts; The cyan ink layer is coated by the cyan ink liquid which is mainly composed of the following components by weight: solvent 90 parts, acrylic resin 30-40 parts, polyurethane resin 10-20 parts, cyan pigment 5-15 parts, filler 5-15 parts and dispersant 0.3-1.5 parts; The thickness of the yellow ink layer in the ink layer (3) is 0.8-2μm, the thickness of the magenta ink layer is 0.8-2μm, and the thickness of the cyan ink layer is 0.8-2μm.

2. The heat transfer sheet for a friction-resistant high-resolution color pattern according to claim 1, wherein The back coating liquid is mainly composed of the following components by weight: solvent 90 parts, polyurethane modified silicone resin 5-15 parts, acrylic modified silicone resin 5-15 parts, polyvinyl acetal resin 20-40 parts, and polyvinyl butyral resin 20-40 parts.

3. The heat transfer sheet for a friction-resistant high-resolution color pattern according to claim 1, wherein The yellow pigment is pigment yellow 14; the magenta pigment is pigment red 48:2; and the cyan pigment is pigment blue 15:

4.

4. The heat transfer sheet for a friction-resistant high-resolution color pattern according to claim 2, wherein The filler is any one or a combination of at least two of talc, calcium carbonate, mica powder, barium sulfate, magnesium sulfate and titanium dioxide; and the solvent is any one or a combination of the two of 2-butanone and toluene.

5. The heat transfer sheet for a friction-resistant high-resolution color pattern according to claim 1, wherein The base (2) is any one of polypropylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene, polyvinyl alcohol and polymethyl methacrylate.

6. The heat transfer sheet for a friction resistant high resolution color pattern according to claim 1, wherein The thickness of the base (2) is 2-15μm, and the thickness of the back coating layer (1) is 0.2-1.0μm.

7. The method for preparing a thermal transfer sheet for a high-resolution color pattern resistant to rubbing according to any one of claims 1 to 6, characterized in that, It comprises the following steps: S1: liquid preparation: Back coating liquid: prepare back coating liquid, standby; Ink liquid: add acrylic resin, polyurethane resin into solvent, then add pigment, filler and dispersant, mix and prepare ink liquid, standby; S2: corona treatment; Provide a substrate (2), corona treatment on both surfaces of the substrate (2); S3: coating; Coat the back coating liquid prepared in step S1 on one surface of the substrate (2) in step S2, then dry to form a back coating layer (1), standby; Coat the ink liquid prepared in step S1 on the surface of the back coating layer (1) away from the substrate (2), then dry to form an ink layer (3), that is, a thermal transfer sheet for high resolution color pattern with abrasion resistance is obtained.

8. The method for preparing a heat transfer film for abrasion-resistant high-resolution color patterns according to claim 7, characterized in that, In step S3, the back coating layer (1) is prepared by coating the back coating liquid with a ceramic anilox roller with a precision of 200-250 lines, the coating speed is 60-100 m / min, the drying temperature is 50-100℃, and the drying time is 40-60s; In the preparation of the ink layer (3), the ink liquid is coated with a ceramic anilox roller with a precision of 200-250 lines, the coating speed is 60-100 m / min, the drying temperature is 40-100℃, and the drying time is 40-60s.

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