Thermal transfer ribbon printing paper and preparation method thereof

Abstract

The invention discloses thermal transfer ribbon printing paper and a preparation method thereof.The preparation method comprises the following steps that the surface of a raw paper base material is coated with precoating paint to form a precoating, then the precoating is coated with surface coating paint to form a surface coating, then the precoating is dried through a drying box till the dryness of paper sheets is larger than or equal to 93%, calendaring is conducted through a six-roller five-pressing-area overpress, the calendaring line pressure ranges from 130 KN / m to 140 KN / m, and the thermal transfer ribbon printing paper is obtained. Rolling to obtain thermal transfer ribbon printing paper; the pre-coating layer comprises light calcium carbonate, heavy calcium carbonate and latex; and the surface coating comprises china clay, heavy calcium carbonate, latex and a starch adhesive. The prepared thermal transfer ribbon printing paper is excellent in wet friction performance, clear in printing effect under different temperature and humidity, free of powder falling, fine and smooth in paper surface, the longitudinal fracture length is larger than 6000 m, the transverse folding strength is larger than 15 times, the transverse expansion and contraction rate is smaller than 2.5%, the smoothness is higher than 800 S, the roughness is smaller than 1.4 microns, the printing speed is high, the color density is higher than 2.0 (wax-based thermal transfer ribbon), thermal transfer printing is clear, lines are full, and white exposure is avoided. Clear transfer printing, full lines and no white exposure of the thermal transfer ribbon can be ensured under extreme temperature and humidity.

Description

Technical Field

[0001] The invention belongs to the technical field of papermaking, and in particular relates to a carbon ribbon printing paper and a preparation method thereof. Background Art

[0002] Carbon ribbon printing paper is a method of printing on paper using a carbon ribbon, where the carbon ribbon is made of a layer of toner and a layer of resin. During the printing process, the print head presses the carbon ribbon and paper together, and uses heat transfer to transfer the toner on the carbon ribbon to the paper to complete the printing.

[0003] Carbon ribbon printing paper is suitable for places where printed content needs to be preserved all year round and is not easy to fade, such as production workshops, hospitals, libraries, archives, etc. This product must meet the paper requirements of barcode printers (using carbon ribbon as the medium), including clear thermal transfer, full lines, no white exposure, non-sticky printing and smooth machine passing, etc. The annual domestic consumption of this product is more than 20,000 tons, and currently it is basically imported products, with high technical barriers. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention provides a carbon ribbon printing paper and a preparation method thereof.

[0005] The object of the present invention is achieved in the following manner: A method for preparing carbon ribbon printing paper comprises the following steps: firstly, coating a pre-coating layer on the surface of an original paper substrate to form a pre-coating layer, then coating a top coating layer on the pre-coating layer to form a top coating layer, then drying the paper sheet in a drying oven until the paper sheet dryness is ≥93%, calendering the paper sheet in a six-roller five-pressure zone super press, the calendering line pressure is 130-140 KN / m, and rolling the paper to obtain the carbon ribbon printing paper; the pre-coating layer comprises the following parts by weight: 40-70 parts of light calcium, 20-30 parts of heavy calcium, and 10-30 parts of latex; and the top coating layer comprises the following parts by weight: 70-75 parts of kaolin, 5-8 parts of heavy calcium, 10-15 parts of latex, and 7-10 parts of starch adhesive.

[0006] The solid content of the pre-coating paint is 10-12%, the viscosity is 100-130CPS, the pH value is 9.0-9.2, and the coating amount is 4.5-5.5g / m2.

[0007] The solid content of the topcoat coating is 13.0-14.0%, the viscosity is 80-120CPS, the pH value is 8.8-9.0, and the coating amount is 9.5-10.5g / m2.

[0008] The drying temperature is controlled at 70-160℃.

[0009] Both the pre-coat and the top coat are applied by curtain coating, with a curtain coating speed of 200-300 m / min, a curtain height of 150-170 mm, and a curtain gap of 20-25 threads.

[0010] The carbon ribbon printing paper prepared by the above preparation method comprises, from bottom to top, a base paper substrate, a pre-coating layer and a top coating layer.

[0011] The base paper is one of thermal base paper, carbonless base paper and offset paper with a gram weight of 55g / m² to 65g / m².

[0012] The carbon ribbon printing paper prepared by the above preparation method has a smoothness higher than 800S, a roughness less than 1.4μm, a wax-based carbon ribbon printing color density higher than 2.0, a longitudinal tear length greater than 6000m, a transverse folding endurance greater than 15 times, a transverse shrinkage rate less than 2.5%, a fast printing speed, clear thermal transfer, full lines, and no white exposure.

[0013] Compared with the prior art, the carbon ribbon printing paper prepared by the present invention first coats the surface of the base paper substrate with a pre-coating layer, and then coats the surface of the pre-coating layer with a topcoating layer. The pre-coating layer and the topcoating layer are well combined, and the wet friction performance is particularly excellent. The printing effect is clear at different temperatures and humidities, and no powder falls off. The paper surface is delicate, the longitudinal tear length is greater than 6000m, the transverse folding endurance is greater than 15 times, the transverse expansion rate is less than 2.5%, the smoothness is higher than 800S, the roughness is less than 1.4μm, the printing speed is fast, the color density is higher than 2.0 (wax-based carbon ribbon), the thermal transfer is clear, the lines are full, and there is no white exposure. The carbon ribbon transfer can also be clear, the lines are full, and there is no white exposure under extreme temperature and humidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 This is a printing effect diagram of the carbon ribbon printing paper prepared in Example 1.

[0016] Figure 3 This is a printing effect diagram of the carbon ribbon printing paper prepared in Example 2.

[0017] Figure 4 This is a printing effect diagram of the carbon ribbon printing paper prepared in Example 3.

[0018] Figure 5 This is a printing effect diagram of the carbon ribbon printing paper prepared in Example 1 after being treated in a constant temperature and humidity chamber at 25° C. and 90% RH for 10 minutes.

[0019] Figure 6 This is a printing effect diagram of the carbon ribbon printing paper prepared in Example 2 after being treated in a constant temperature and humidity chamber at 25° C. and 90% RH for 10 minutes.

[0020] Figure 7 This is a printing effect diagram of the carbon ribbon printing paper prepared in Example 3 after being treated in a constant temperature and humidity chamber at 25° C. and 90% RH for 10 minutes. Detailed implementation mode

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the present invention.

[0022] A preparation method of a carbon ribbon printing paper includes the following steps: coating a precoat paint on the surface of the base paper substrate 1 to form a precoat 2, then coating a topcoat paint on the precoat 2 to form a topcoat 3, and then entering a drying oven with the drying temperature controlled at 70-160°C, drying until the paper dryness is ≥93%, passing through a six-roll five-pressure zone supercalender for calendering, with the calender line pressure being 130-140 KN / m, and winding to obtain the carbon ribbon printing paper; the precoat paint includes the following parts by weight of light calcium carbonate 40-70 parts, heavy calcium carbonate 20-30 parts, and latex 10-30 parts; the topcoat paint includes the following parts by weight of kaolin 70-75 parts, heavy calcium carbonate 5-8 parts, latex 10-15 parts, and starch adhesive 7-10 parts.

[0023] Light calcium carbonate, heavy calcium carbonate, and kaolin are all coating pigments. Compared with heavy calcium carbonate, light calcium carbonate has higher brightness and ink absorbency. The pigments selected for the precoat are heavy calcium carbonate and light calcium carbonate, which can not only meet the requirements but also appropriately reduce costs. Kaolin has high whiteness, fine particle size, a thin-layer structure of particles, and good hiding power, and can provide a smooth coating and gloss. Both latex and starch are used as adhesives, which play a role in bonding pigment particles and between pigments and fibers, ensuring firm bonding between the coating and the base paper and improving surface strength. First, coat the precoat. The paint binds tightly with the paper fibers, endowing the precoated paper with higher smoothness and fineness. Then, coat the topcoat to further improve the smoothness of the paper, reduce roughness, and improve the printing effect. The precoat provides better smoothness and fineness of the coating. The topcoat paint is a white paint that can completely cover the precoat. After drying and supercalendering treatment, a thermal transfer engineering drawing with high smoothness, small roughness, and good printing effect is obtained.

[0024] The solid content of the precoat paint is 10-12%, the viscosity is 100-130 CPS, the PH value is 9.0-9.2, and the coating amount is 4.5-5.5 g / m 2 ; the solid content of the topcoat paint is 13.0-14.0%, the viscosity is 80-120 CPS, the PH value is 8.8-9.0, and the coating amount is 9.5-10.5 g / m 2 .

[0025] Both the precoat 2 and the topcoat 3 are coated by the curtain coating method. The curtain coating speed is 200-300 m / min, the curtain height is 150-170 mm, and the curtain slit is 20-25 filaments.

[0026] The carbon ribbon printing paper prepared by the above preparation method comprises a base paper substrate 1, a pre-coating layer 2 and a top coating layer 3 from bottom to top. Figure 1 The base paper substrate 1 is selected from thermal base paper, carbonless base paper, and offset paper with a gram weight of 55g / m² to 65g / m². The carbon ribbon printing paper prepared by the above preparation method has a smoothness higher than 800S, a roughness lower than 1.4μm, a wax-based carbon ribbon printing color density higher than 2.0, a longitudinal tear length greater than 6000m, a transverse folding endurance greater than 15 times, a transverse shrinkage rate less than 2.5%, a fast printing speed, clear thermal transfer, full lines, and no white exposure.

[0027] Example 1 A carbon ribbon printing paper is prepared by the following steps: (1) Prepare the pre-coat paint Disperse the following weight portions of light calcium 40 parts, heavy calcium 30 parts, and latex 30 parts uniformly to form a pre-coating coating with a solid content of 11%, a viscosity of 100 CPS, and a pH value of 9.2; (2) Prepare topcoat paint The following weight parts of china clay 70 parts, heavy calcium 5 parts, latex 15 parts, starch adhesive 10 parts are evenly dispersed to form a top coating with a solid content of 13.0%, a viscosity of 120 CPS, and a pH value of 8.8; (3) Prepare a thermal base paper with a gram weight of 55 g / m² as the base paper substrate 1, apply a pre-coating coating on the surface of the thermal base paper to form a pre-coating 2, and then apply a top coating coating on the pre-coating 2 to form a top coating 3. Apply the pre-coating 2 and the top coating 3 by curtain coating respectively. The speed of the curtain coating is 200 m / min, the curtain height is 170 mm, the curtain gap is 20 threads, and the coating amount of the pre-coating is 4.5 g / m 2 The coating weight of the top coating is 10.5g / m 2 ; (4) After the topcoat 3 is applied, it enters a multi-section drying oven for drying. The temperature curve is controlled at 160-150-130-80-60-100-90°C. It is dried to a paper dryness of ≥93%. It is calendered by a six-roller five-pressure zone super press with a calendering line pressure of 130KN / m, and a 70gsm carbon ribbon printing paper is obtained by rolling.

[0028] The carbon ribbon printing paper prepared by the above method was subjected to a printing test, and the breaking length, folding endurance, shrinkage rate, smoothness and roughness were tested according to GB / T 12914-2018, GB / T 457-2008, GB / T 459-2002, GB / T 456-2002 and GB / T 22363-2009, respectively. The longitudinal breaking length was 6800m, the transverse folding endurance was 20 times, the transverse shrinkage rate was 1.8%, the smoothness was higher than 950S, the roughness was less than 1.10μm, the printing speed was fast, the carbon ribbon transfer was clear, the lines were full, there was no whitening, and the printing speed was fast. Figure 2 .

[0029] The color density test method is as follows: cut the carbon ribbon printing paper horizontally, with a width of about 110mm; for the ZT410 printer, select the thermal transfer printing mode; print concentration / speed (inch): D12×S12, or set as required (the color density mentioned below does not specify the printing conditions, all are completed under the conditions of D12×S12); use the wax-based carbon ribbon to print according to the barcode pattern set in advance; use a reflective color densitometer to test the color density and get a color density of 2.31.

[0030] The carbon ribbon printing paper prepared by the above preparation method was treated in a constant temperature and humidity chamber at 25°C and 90%RH for 10 minutes, and then printed. The carbon ribbon transfer was still clear, the lines were full, there was no white exposure, and the print color density was 2.36. Figure 5 .

[0031] Example 2 A carbon ribbon printing paper is prepared by the following steps: (1) Prepare the pre-coat paint Disperse the following parts by weight of light calcium 50 parts, heavy calcium 25 parts, and latex 25 parts uniformly to form a pre-coating paint with a solid content of 12%, a viscosity of 120 CPS, and a pH value of 9.0; (2) Prepare topcoat paint The following weight parts of china clay 73 parts, heavy calcium 8 parts, latex 12 parts, starch adhesive 7 parts are evenly dispersed to form a top coating with a solid content of 13.5%, a viscosity of 100 CPS, and a pH value of 8.9; (3) Prepare carbonless base paper with a gram weight of 55g / m² as base paper substrate 1, apply pre-coating coating on the surface of carbonless base paper to form pre-coating 2, and then apply top coating coating on pre-coating 2 to form top coating 3. Apply pre-coating 2 and top coating 3 by curtain coating respectively. The speed of curtain coating is 250m / min, the curtain height is 160mm, the curtain gap is 23 wires, and the coating amount of pre-coating is 5.0g / m 2 The coating weight of the top coating is 10.0g / m 2 ; (4) After the topcoat 3 is applied, it enters a multi-section drying oven for drying. The temperature curve is controlled at 160-150-140-90-70-100-90°C. It is dried until the paper dryness is ≥93%. It is calendered by a six-roller five-pressure zone super press with a calendering line pressure of 135KN / m, and the 70gsm carbon ribbon printing paper is rolled up.

[0032] The carbon ribbon printing paper prepared by the above method has a longitudinal tear length of 6500m, a transverse folding endurance of 17 times, a transverse shrinkage rate of 2.2%, a smoothness higher than 850S, a roughness less than 1.20μm, a fast printing speed, clear carbon ribbon transfer, full lines, no white exposure, and a color density of 2.18 (wax-based carbon ribbon). Figure 4 .

[0033] The paper sample was treated in a constant temperature and humidity chamber at 25℃ and 90%RH for 10 minutes and then printed. The carbon ribbon transfer was still clear, the lines were full, there was no white exposure, and the print color density was 2.20. Figure 6 .

[0034] Example 3 The difference between this embodiment and embodiment 1 is that 70 parts of light calcium, 20 parts of heavy calcium and 10 parts of latex are evenly dispersed to form a pre-coating coating with a solid content of 10%, a viscosity of 130CPS and a pH value of 9.1; 75 parts of china clay, 7 parts of heavy calcium, 10 parts of latex and 8 parts of starch adhesive are evenly dispersed to form a top coating with a solid content of 14.0%, a viscosity of 80CPS and a pH value of 9.0; the base paper substrate 1 is a double-coated paper with a gram weight of 65 g / m²; the speed of the curtain coating is 300m / min, the curtain height is 150mm, the curtain gap is 25 threads, and the pre-coating coating amount is 5.5g / m 2 The coating weight of the top coating is 9.5g / m 2 The drying temperature curve was controlled at 160-150-140-90-60-90-80°C, the calendering pressure was 140 KN / m, and 80 gsm carbon ribbon printing paper was obtained.

[0035] After testing, the carbon ribbon printing paper prepared in this embodiment has a longitudinal tear length of 7500m, a transverse folding endurance of 18 times, a transverse expansion rate of 2.5%, a smoothness of 800S, a roughness of 1.40μm, a color density of 2.10 (wax-based carbon ribbon), a fast printing speed, clear carbon ribbon transfer, full lines, no white exposure, and a Figure 5 The paper sample was treated in a constant temperature and humidity chamber at 25℃ and 90%RH for 10 minutes and then printed. The carbon ribbon transfer was still clear, the lines were full, there was no white, and the print color density was 2.12. Figure 7 .

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, which should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing carbon ribbon printing paper, characterized in that: The method comprises the following steps: firstly, applying a pre-coating coating on the surface of a base paper substrate (1) to form a pre-coating (2); then applying a top coating coating on the pre-coating (2) to form a top coating (3); then drying the paper sheet in a drying oven until the paper sheet dryness is ≥93%; calendering the paper sheet in a six-roller five-pressure zone super press with a calendering line pressure of 130-140 KN / m; and rolling the paper to obtain a carbon ribbon printing paper; the pre-coating coating comprises the following parts by weight: 40-70 parts of light calcium, 20-30 parts of heavy calcium, and 10-30 parts of latex; and the top coating coating comprises the following parts by weight: 70-75 parts of kaolin, 5-8 parts of heavy calcium, 10-15 parts of latex, and 7-10 parts of starch adhesive.

2. The method for preparing carbon ribbon printing paper according to claim 1, characterized in that: The solid content of the pre-coating paint is 10-12%, the viscosity is 100-130CPS, the pH value is 9.0-9.2, and the coating amount is 4.5-5.5g / m 2 .

3. The method for preparing carbon ribbon printing paper according to claim 1, characterized in that: The solid content of the top coating is 13.0-14.0%, the viscosity is 80-120CPS, the pH value is 8.8-9.0, and the coating amount is 9.5-10.5g / m 2 .

4. The method for preparing carbon ribbon printing paper according to claim 1, characterized in that: The drying temperature is controlled at 70-160℃.

5. The method for preparing carbon ribbon printing paper according to claim 1, characterized in that: The pre-coat layer (2) and the top coat layer (3) are both coated by curtain coating, with a curtain coating speed of 200-300 m / min, a curtain height of 150-170 mm, and a curtain gap of 20-25 threads.

6. The carbon ribbon printing paper prepared by the preparation method according to any one of claims 1 to 5, characterized in that: From bottom to top, it includes a base paper substrate (1), a pre-coating layer (2) and a top coating layer (3).

7. The carbon ribbon printing paper according to claim 6, characterized in that: The base paper substrate (1) is one of thermal base paper, carbonless base paper and offset paper with a grammage of 55 g / m² to 65 g / m².

8. The carbon ribbon printing paper according to claim 6, characterized in that: The smoothness is higher than 800S, the roughness is less than 1.4μm, the wax-based carbon ribbon printing color density is higher than 2.0, the longitudinal tear length is greater than 6000m, the transverse folding endurance is greater than 15 times, the transverse shrinkage rate is less than 2.5%, the printing speed is fast, the thermal transfer is clear, the lines are full, and there is no white exposure.

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