Anti-settling inorganic pigment color-changeable anti-counterfeiting printing ink and preparation method thereof

Abstract

The application provides a preparation method of a non-settling inorganic pigment variable color anti-counterfeiting printing ink. The filler and the pigment are prepared into slurries separately, the particle size mismatch is formed among the three fillers by controlling the particle size of the filler, the particle size mismatched filler is fully wrapped by the resin in the mixing process with part of the polyvinyl butyral slurry, the mixed slurry with good suspension effect is formed, the mixed slurry is low-speed ground together with the organic bentonite, and the suspension performance of the mixed slurry is further improved. On this basis, the acrylic slurry and the temperature-sensitive color-changing capsule are added for dispersion, the pigment filler is further wrapped by the resin, finally, the remaining polyvinyl butyral slurry and the additive are used for conditioning to improve the viscosity of the material. The anti-counterfeiting ink obtained in this way has high anti-counterfeiting performance, basically no precipitation after long-term storage, and good use performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anti-counterfeiting ink, in particular to an anti-settling inorganic pigment variable color anti-counterfeiting printing ink and a preparation method thereof. BACKGROUND

[0002] Anti-counterfeiting ink is a special ink with anti-counterfeiting function by adding some special substances in the ink, which can change under special conditions to print visible or invisible marks for verification and prevention of counterfeiting. Anti-counterfeiting ink is an extremely important anti-counterfeiting technology field, which is applied to print anti-counterfeiting printed products and has a wide range of applications.

[0003] Pigments and fillers are generally added to anti-counterfeiting ink to enhance product performance and reduce costs, such as inorganic pigments of yellow and red iron oxide, and fillers of titanium dioxide and talc. Some inks may contain a high content of pigments and fillers according to requirements. The pigments and fillers have a large specific gravity, and in this case, the resin cannot be fully wrapped, thereby causing a serious problem of ink settlement after storage.

[0004] The settlement of ink can cause uneven dispersion during printing, affect the printing concentration, and cannot restore the sample color phase, thereby affecting the printing quality, and even the settlement slurry cannot be used to form solid waste. Therefore, while studying the anti-counterfeiting performance of anti-counterfeiting ink, the settlement of the ink also needs to be considered to improve the use performance of the ink. SUMMARY

[0005] The present application aims to solve the problem of easy settlement of ink with a large specific gravity of pigments and fillers, and provides an anti-settling inorganic pigment variable color anti-counterfeiting printing ink and a preparation method thereof. By designing the proportioning and adjusting the preparation process, the problem of ink settlement after long-term storage is solved, the use performance of the ink is improved, and the subsequent printing quality is ensured.

[0006] According to the first aspect of the present application, a preparation method of an anti-settling inorganic pigment variable color anti-counterfeiting printing ink is provided, which comprises the following steps:

[0007] Step 1, the raw materials are weighed according to the proportion, and the water-based acrylic emulsion, part of the water-soluble polyvinyl butyral, titanium dioxide, calcium carbonate, talc, and inorganic pigments are respectively mixed into acrylic slurry, polyvinyl butyral slurry, titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry by using a solubilizing agent; wherein the particle size of titanium dioxide, calcium carbonate, and talc is different, thereby forming a mismatch of different particle sizes;

[0008] Step 2, under the condition of stirring, the titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry are sequentially added to the polyvinyl butyral slurry, and stirred and dispersed uniformly to obtain a mixed slurry;

[0009] Step 3, sequentially add the mixed slurry, organic bentonite, and part of the deionized water into the grinder at one time, and grind to the required fineness at a speed of not more than 250 kg / h to obtain an intermediate material;

[0010] Step 4, put the intermediate material and the acrylic slurry into the reaction kettle and disperse uniformly, then put into the thermochromic capsule and continue to stir and disperse uniformly to obtain the ink precursor;

[0011] Step 5, mix the remaining polyvinyl butyral slurry, the remaining deionized water, and the remaining cosolvent uniformly to obtain an adjusting liquid, and add the adjusting liquid into the ink precursor to adjust the color concentration and viscosity, and then filter to obtain the anti-settling inorganic pigment variable color anti-counterfeiting printing ink.

[0012] As an optional embodiment, the raw materials of the ink include, in terms of weight percentage, 12% to 18% water-soluble resin, 15% to 30% deionized water, 10% to 15% cosolvent, 10% to 15% thermochromic capsule, 8% to 15% inorganic pigment, 25% to 35% filler, and 2% to 4% organic bentonite; wherein the water-soluble resin includes water-soluble polyvinyl butyral and water-based acrylic emulsion, and the filler includes titanium dioxide, calcium carbonate, and talc.

[0013] As an optional embodiment, the mass ratio of the water-soluble polyvinyl butyral and the water-based acrylic emulsion is (2 to 4):(5 to 7).

[0014] As an optional embodiment, the mass ratio of the titanium dioxide, the calcium carbonate, and the talc is (5 to 3):(1 to 2):1, and the particle size relationship of the titanium dioxide, the calcium carbonate, and the talc is titanium dioxide < calcium carbonate < talc.

[0015] As an optional embodiment, the inorganic pigment includes yellow iron oxide and red iron oxide.

[0016] As an optional embodiment, the mass ratio of the yellow iron oxide and the red iron oxide is 1:1.

[0017] As an optional embodiment, the cosolvent is a combination of one or more of ethanol, isopropyl alcohol, and n-propanol.

[0018] As an optional embodiment, in steps 1 and 5, the use mass ratio of the cosolvent is (7 to 9):(1 to 3), and the use mass ratio of the water-soluble polyvinyl butyral is (7 to 9):(1 to 3).

[0019] As an optional embodiment, in steps 3 and 5, the use mass ratio of the deionized water is (7 to 9):(1 to 3).

[0020] According to a second aspect of the present application, there is provided a non-settleable inorganic pigment variable color anti-counterfeiting printing ink prepared by the method described above.

[0021] As can be seen from the technical solutions of the present application, the preparation method of the non-settleable inorganic pigment variable color anti-counterfeiting printing ink provided by the present application first prepares slurries of fillers and pigments separately, controls the particle size of the fillers, and forms a particle size mismatch among the three fillers. During the mixing process with part of the polyvinyl butyral slurry, the fillers with a particle size mismatch are fully wrapped by the resin, forming a mixed slurry with good suspension effect. The mixed slurry is then ground at low speed together with the organic bentonite, further improving the suspension performance of the mixed slurry. On this basis, the acrylic slurry and the temperature-sensitive color-changing capsules are added for dispersion, so that the pigments and fillers are further wrapped by the resin. Finally, the remaining polyvinyl butyral slurry and the additives are used for conditioning to improve the viscosity of the material. The anti-counterfeiting ink obtained in this way has high anti-counterfeiting performance and basically no sedimentation after long-term storage, and has good use performance. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a picture of the sedimentation performance test in the example of the present application. DETAILED DESCRIPTION

[0023] In order to better understand the technical content of the present application, specific embodiments are described below with reference to the accompanying drawings.

[0024] Aspects of the present application are described in the disclosure by reference to the accompanying drawings, in which a number of illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to include all aspects of the present application. It should be understood that various concepts and embodiments introduced above, and those described in more detail below, can be implemented in any of numerous ways.

[0025] In an exemplary embodiment of the present application, a preparation method of a non-settleable inorganic pigment variable color anti-counterfeiting printing ink is provided, which comprises the following steps:

[0026] Step 1: The raw materials are weighed according to the proportion, and the water-based acrylic emulsion, part of the water-soluble polyvinyl butyral, titanium dioxide, calcium carbonate, talc, and inorganic pigments are respectively prepared into acrylic slurry, polyvinyl butyral slurry, titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry by using a cosolvent; wherein the particle sizes of the titanium dioxide, calcium carbonate, and talc are different, thereby forming a mismatch of different particle sizes;

[0027] Step 2: Under the condition of stirring, the titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry are sequentially added to the polyvinyl butyral slurry, and stirred and dispersed uniformly to obtain a mixed slurry;

[0028] Step 3, sequentially add the mixed slurry, organic bentonite, and part of the deionized water into the grinder, and grind to the required fineness at a speed of not more than 250 kg / h, to obtain an intermediate material;

[0029] Step 4, add the intermediate material and the acrylic slurry into a reaction kettle and disperse uniformly, then add the thermochromic capsule and continue to stir and disperse uniformly, to obtain an ink precursor;

[0030] Step 5, mix the remaining polyvinyl butyral slurry, the remaining deionized water, and the remaining cosolvent uniformly to obtain an adjusting liquid, and add the adjusting liquid into the ink precursor to adjust the color concentration and viscosity, and after filtration, an anti-settling inorganic pigment variable color anti-counterfeiting printing ink is obtained.

[0031] As an optional embodiment, the raw materials of the ink include, in terms of weight percentage, 12% to 18% of water-soluble resin, 15% to 30% of deionized water, 10% to 15% of cosolvent, 10% to 15% of thermochromic capsule, 8% to 15% of inorganic pigment, 25% to 35% of filler, and 2% to 4% of organic bentonite; wherein the water-soluble resin includes water-soluble polyvinyl butyral and water-based acrylic emulsion, and the filler includes titanium dioxide, calcium carbonate, and talc.

[0032] As an optional embodiment, the mass ratio of the water-soluble polyvinyl butyral and the water-based acrylic emulsion is (2 to 4):(5 to 7).

[0033] As an optional embodiment, the mass ratio of the titanium dioxide, the calcium carbonate, and the talc is (5 to 3):(1 to 2):1, and the particle size size relationship of the titanium dioxide, the calcium carbonate, and the talc is: titanium dioxide < calcium carbonate < talc.

[0034] In one preferred embodiment, the particle size range of the titanium dioxide is 0.2 to 1 μm, the particle size range of the calcium carbonate is 10 to 20 μm, and the particle size range of the talc is 30 to 40 μm.

[0035] It should be understood that the above particle size refers to the median particle size of the powder, i.e. the value of D50.

[0036] As an optional embodiment, the inorganic pigment includes yellow iron oxide and red iron oxide.

[0037] As an optional embodiment, the mass ratio of the yellow iron oxide and the red iron oxide is 1:1.

[0038] As an optional embodiment, the color change temperature of the thermochromic capsule is 0 to 70℃.

[0039] It can be understood that the inorganic pigment includes but is not limited to yellow iron oxide and red iron oxide, and can be selected and matched according to the actual color requirement, and the color of the required color change can also be selected according to the actual situation.

[0040] As an optional embodiment, the cosolvent is a combination of one or more of ethanol, isopropanol, and n-propanol.

[0041] As an optional embodiment, in steps 1 and 5, the mass ratio of the cosolvent used is (7-9):(1-3), and the mass ratio of the water-soluble polyvinyl butyral used is (7-9):(1-3).

[0042] As an optional embodiment, in steps 3 and 5, the mass ratio of the deionized water used is (7-9):(1-3).

[0043] In another exemplary embodiment of the present application, a non-settling inorganic pigment variable color anti-counterfeiting printing ink prepared by the above method is also provided, which is substantially free of precipitation after 30 days, has good performance, and has excellent anti-counterfeiting performance.

[0044] In order to better understand, the present application will be further described below in conjunction with specific examples, but the processing process is not limited thereto, and the content of the present application is not limited thereto.

[0045] The reagents used in the following examples are all commercially available unless otherwise specified.

[0046] Among them, the particle size range of titanium dioxide used is 0.2-1 μm, the particle size range of calcium carbonate is 10-20 μm, and the particle size range of talc is 30-40 μm; the mass ratio of titanium dioxide, calcium carbonate and talc is 3:1:1.

[0047] The mass ratio of water-soluble polyvinyl butyral and water-based acrylic emulsion is 1:3, the inorganic pigment is yellow iron oxide and red iron oxide, the mass ratio is 1:1; the cosolvent is ethanol, and the temperature-sensitive color-changing capsule is yellow.

[0048] Example 1

[0049] [Preparation of water-soluble polyvinyl butyral]

[0050] At room temperature, 12 g of 0.002 mol polyvinyl butyral, 9 g of 0.0608 mol phthalic anhydride, 0.126 g of 0.0039 mol tetrabutylammonium bromide and 200 mL of dimethylformamide were added into a four-necked flask, stirred uniformly, and gradually heated to 60°C during stirring, then reacted at 60°C for 6 h, then the reaction was stopped, 100 mL of acetone solution was added after cooling, and stirring was continued for 30 min, then the mixture was uniformly dispersed in distilled water, and the dispersion was repeatedly filtered, and the filter cake was dried to obtain a water-soluble polyvinyl butyral.

[0051] Example 2

[0052] Step 1: The raw materials were weighed according to the proportion, 18% water-soluble resin, 20% deionized water, 10% cosolvent, 10% temperature-sensitive color-changing capsule, 13% inorganic pigment, 27% filler, and 2% organic bentonite.

[0053] The water-based acrylic emulsion, part of the water-soluble polyvinyl butyral (prepared according to the method of Example 1), titanium dioxide, calcium carbonate, talc, and inorganic pigment were respectively dissolved in the cosolvent to prepare an acrylic slurry, a polyvinyl butyral slurry, a titanium dioxide slurry, a calcium carbonate slurry, a talc slurry, and an inorganic pigment slurry.

[0054] Step 2: Under stirring, the titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry were sequentially added to the polyvinyl butyral slurry, and stirred and dispersed uniformly at a speed of 1000 rmp to obtain a mixed slurry.

[0055] Step 3: The mixed slurry, organic bentonite, and part of the deionized water were sequentially added to a grinder and ground to the required fineness ≤15 μm at a speed of 250 kg / h to obtain an intermediate material.

[0056] Step 4: The intermediate material and the acrylic slurry were put into a reaction kettle and dispersed uniformly at a speed of 800 rmp, then the temperature-sensitive color-changing capsule was put in and stirred and dispersed uniformly at a speed of 800 rmp to obtain an ink precursor.

[0057] Step 5: The remaining polyvinyl butyral slurry, the remaining deionized water, and the remaining cosolvent were mixed uniformly to obtain an adjusting solution, and the adjusting solution was added to the ink precursor for color concentration and viscosity adjustment, and then filtered to obtain a non-settleable inorganic pigment variable color anti-counterfeiting printing ink.

[0058] In step 1 and step 5, the mass ratio of the cosolvent used is 7:3, and the mass ratio of the water-soluble polyvinyl butyral used is 9:1; in step 3 and step 5, the mass ratio of the deionized water used is 9:1.

[0059] Example 3

[0060] Step 1, the raw materials are weighed in proportion, 12% water-soluble resin, 15% deionized water, 15% cosolvent, 11% thermochromic capsule, 8% inorganic pigment, 35% filler, 4% organic bentonite;

[0061] The water-based acrylic emulsion, part of the water-soluble polyvinyl butyral (prepared according to the method of Example 1), titanium dioxide, calcium carbonate, talc, inorganic pigment are respectively prepared into acrylic slurry, polyvinyl butyral slurry, titanium dioxide slurry, calcium carbonate slurry, talc slurry and inorganic pigment slurry by using cosolvent.

[0062] Step 2, under the condition of stirring, the titanium dioxide slurry, calcium carbonate slurry, talc slurry and inorganic pigment slurry are sequentially added into the polyvinyl butyral slurry, and stirred and dispersed uniformly at a speed of 1000 rmp to obtain a mixed slurry.

[0063] Step 3, the mixed slurry, organic bentonite and part of the deionized water are sequentially added into a grinding machine, and ground to the required fineness ≤15 μm at a speed of 250 kg / h to obtain an intermediate material.

[0064] Step 4, the intermediate material and the acrylic slurry are put into a reaction kettle, dispersed uniformly at a speed of 800 rmp, and then the thermochromic capsule is put in to continue stirring and dispersing uniformly at a speed of 800 rmp to obtain an ink precursor.

[0065] Step 5, the remaining polyvinyl butyral slurry, the remaining deionized water and the remaining cosolvent are mixed uniformly to obtain an adjusting liquid, and the adjusting liquid is added into the ink precursor for color concentration and viscosity adjustment, and the anti-settling inorganic pigment variable color anti-counterfeiting printing ink is obtained after filtration.

[0066] In step 1 and step 5, the mass ratio of the cosolvent is 4:1, and the mass ratio of the water-soluble polyvinyl butyral is 4:1; in step 3 and step 5, the mass ratio of the deionized water is 4:1

[0067] Example 4

[0068] Step 1, the raw materials are weighed in proportion, 15% water-soluble resin, 25% deionized water, 10% cosolvent, 10% thermochromic capsule, 13% inorganic pigment, 25% filler, 2% organic bentonite;

[0069] The water-based acrylic emulsion, part of the water-soluble polyvinyl butyral (prepared according to the method of Example 1), titanium dioxide, calcium carbonate, talc, inorganic pigment are respectively prepared into acrylic slurry, polyvinyl butyral slurry, titanium dioxide slurry, calcium carbonate slurry, talc slurry and inorganic pigment slurry by using cosolvent.

[0070] Step 2, under the condition of stirring, the titanium dioxide slurry, calcium carbonate slurry, talc slurry and inorganic pigment slurry were sequentially added into the polyvinyl butyral slurry, and stirred and dispersed uniformly at a speed of 1000 rmp to obtain a mixed slurry.

[0071] Step 3, the mixed slurry, organic bentonite and part of deionized water were sequentially added into a grinding machine, and ground to a required fineness of ≤15 μm at a speed of 250 kg / h to obtain an intermediate material.

[0072] Step 4, the intermediate material and the acrylic acid slurry were put into a reaction kettle, and dispersed uniformly at a speed of 800 rmp, and then the thermochromic capsule was put in and stirred and dispersed uniformly at a speed of 800 rmp to obtain an ink precursor.

[0073] Step 5, the remaining polyvinyl butyral slurry, the remaining deionized water and the remaining cosolvent were mixed uniformly to obtain an adjusting liquid, and the adjusting liquid was added into the ink precursor for color concentration and viscosity adjustment, and after filtration, a non-settleable inorganic pigment variable color anti-counterfeiting printing ink was obtained.

[0074] In steps 1 and 5, the mass ratio of the cosolvent used is 9:1, and the mass ratio of the water-soluble polyvinyl butyral used is 7:3; in steps 3 and 5, the mass ratio of the deionized water used is 7:3.

[0075] Comparative Example 1

[0076] Step 1, the raw materials were weighed according to the proportion, 17% water-soluble resin, 25% deionized water, 10% cosolvent, 10% thermochromic capsule, 13% inorganic pigment, 25% filler;

[0077] The raw materials were sequentially and once added into a grinding machine, and ground to a required fineness of ≤15 μm at a speed of 600 kg / h to obtain an intermediate material, and the intermediate material was tempered to obtain an anti-counterfeiting ink.

[0078] In steps 1 and 5, the mass ratio of the cosolvent used is 9:1, and the mass ratio of the water-soluble polyvinyl butyral used is 7:3; in steps 3 and 5, the mass ratio of the deionized water used is 7:3.

[0079] Comparative Example 2

[0080] Step 1, the raw materials were weighed according to the proportion, 17% water-soluble resin, 25% deionized water, 10% cosolvent, 10% thermochromic capsule, 13% inorganic pigment, 25% filler, 2% organic bentonite;

[0081] The raw materials were sequentially and once added into a grinding machine, and ground to a required fineness of ≤15 μm at a speed of 600 kg / h to obtain an intermediate material, and the intermediate material was tempered to obtain an anti-counterfeiting ink.

[0082] wherein the water-soluble polyvinyl butyral is prepared according to the method of Example 1.

[0083] Comparative Example 3

[0084] Step 1, the raw materials are weighed in proportion, 15% water-soluble resin, 25% deionized water, 10% cosolvent, 10% thermochromic capsule, 13% inorganic pigment, 25% filler, 2% organic bentonite;

[0085] The water-based acrylic emulsion, part of the water-soluble polyvinyl butyral (prepared according to the method of Example 1), titanium dioxide, calcium carbonate, talc, and inorganic pigment are respectively dissolved in cosolvent to prepare an acrylic slurry, a polyvinyl butyral slurry, a titanium dioxide slurry, a calcium carbonate slurry, a talc slurry, and an inorganic pigment slurry.

[0086] Step 2, under the condition of stirring, the titanium dioxide slurry, the calcium carbonate slurry, the talc slurry, and the inorganic pigment slurry are sequentially added to the polyvinyl butyral slurry, and stirred and dispersed uniformly at a speed of 1000 rmp to obtain a mixed slurry.

[0087] Step 3, the mixed slurry and part of the deionized water are sequentially added to a grinding machine, and ground to a desired fineness of ≤15 μm at a speed of 600 kg / h to obtain an intermediate material.

[0088] Step 4, the intermediate material and the acrylic slurry are put into a reaction kettle, and dispersed uniformly at a speed of 800 rmp, and then the thermochromic capsule is put in and stirred and dispersed uniformly at a speed of 800 rmp to obtain an ink precursor.

[0089] Step 5, the remaining polyvinyl butyral slurry and the remaining deionized water are mixed uniformly to obtain an adjusting liquid, and the adjusting liquid is added to the ink precursor for color concentration and viscosity adjustment, and after filtration, a non-sedimentation inorganic pigment variable color anti-counterfeiting printing ink is obtained.

[0090] In step 1 and step 5, the use mass ratio of water-soluble polyvinyl butyral is 7:3; in step 3 and step 5, the use mass ratio of deionized water is 7:3.

[0091] Comparative Example 4

[0092] Step 1, the raw materials are weighed in proportion, 15% water-soluble resin, 25% deionized water, 10% cosolvent, 10% thermochromic capsule, 13% inorganic pigment, 25% filler, 2% organic bentonite;

[0093] The water-based acrylic emulsion, part of water-soluble polyvinyl butyral (prepared according to the method of Example 1), titanium dioxide, calcium carbonate, talc, and inorganic pigments were respectively formulated into acrylic slurry, polyvinyl butyral slurry, titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry by using a co-solvent.

[0094] Step 2, under the condition of stirring, the titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry were sequentially added into the polyvinyl butyral slurry, and stirred and dispersed uniformly at a speed of 1000 rmp to obtain a mixed slurry.

[0095] Step 3, the mixed slurry, organic bentonite, and part of deionized water were sequentially added into a grinder, and ground to a required fineness of ≤15 μm at a speed of 600 kg / h to obtain an intermediate material.

[0096] Step 4, the intermediate material and the acrylic slurry were put into a reaction kettle, and dispersed uniformly at a speed of 800 rmp, and then the thermochromic capsule was put in and stirred and dispersed uniformly at a speed of 800 rmp to obtain an ink precursor.

[0097] Step 5, the remaining polyvinyl butyral slurry, the remaining deionized water, and the remaining co-solvent were mixed uniformly to obtain an adjusting liquid, and the adjusting liquid was added into the ink precursor for adjusting the color concentration and viscosity, and after filtration, a non-sedimentation inorganic pigment variable color anti-counterfeiting printing ink was obtained.

[0098] In steps 1 and 5, the use mass ratio of the co-solvent was 9:1, and the use mass ratio of the water-soluble polyvinyl butyral was 7:3; in steps 3 and 5, the use mass ratio of the deionized water was 7:3.

[0099] Performance Test

[0100] The ink samples of Examples 2-4 and Comparative Examples 1-4 were subjected to performance tests, and the results are shown in Table 1.

[0101] Table 1

[0102] Viscosity / s Fineness / pm Coloring power / % Anti-curling property Discoloration Example 2 35 ≤15 98 No curling deformation Discoloration was obvious Example 3 35 ≤15 100 No curling deformation Discoloration was obvious Example 4 40 ≤15 100 No curling deformation Discoloration was obvious Comparative Example 1 30 ≤15 95 Slight curling Discoloration was obvious Comparative Example 2 35 ≤15 95 Slight curling Discoloration was obvious Comparative Example 3 40 ≤15 98 No curling deformation Discoloration was obvious Comparative Example 4 40 ≤15 100 No curling deformation Discoloration was obvious

[0103] Precipitation Test

[0104] The ink samples of Example 4 and Comparative Examples 1-4 were respectively filled into bottles, and the filled weights were equal. After being placed for 30 days, the precipitation was observed.

[0105] It was observed that the sample of Example 4 had basically no precipitation and good suspension performance, and the samples of Comparative Examples 1-4 all had obvious stratification, especially the sample of Comparative Example 1, which had much precipitation and was difficult to stir, as shown in Fig. 1. Figure 1 It was observed that the sample of Example 4 had basically no precipitation and good suspension performance, and the samples of Comparative Examples 1-4 all had obvious stratification, especially the sample of Comparative Example 1, which had much precipitation and was difficult to stir, as shown in Fig. 1.

[0106] From the above, the anti-fake ink obtained by designing components and adjusting the process has excellent anti-settling performance and maintains excellent anti-fake performance.

[0107] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the present application. Those skilled in the art, without departing from the spirit and scope of the present application, can make various modifications and improvements. Therefore, the scope of protection of the present application is defined by the claims.

Claims

1. A process for the preparation of a non-settling inorganic pigment variable color security printing ink characterized in that, The method comprises the following steps: Step 1, proportionally weigh each raw material, and use a cosolvent to respectively prepare an acrylic slurry, a polyvinyl butyral slurry, a titanium dioxide slurry, a calcium carbonate slurry, a talc slurry, and an inorganic pigment slurry from the water-based acrylic emulsion, part of the water-soluble polyvinyl butyral, titanium dioxide, calcium carbonate, talc, and inorganic pigment; wherein the particle sizes of the titanium dioxide, calcium carbonate, and talc are different, and the relationship between the particle sizes of the titanium dioxide, calcium carbonate, and talc is: titanium dioxide < calcium carbonate < talc, so as to form a mismatch of different particle sizes; Step 2, under the condition of stirring, sequentially add the titanium dioxide slurry, calcium carbonate slurry, talc slurry, and inorganic pigment slurry into the polyvinyl butyral slurry, and stir to uniformly disperse, to obtain a mixed slurry; Step 3, sequentially add the mixed slurry, organic bentonite, and part of deionized water into a grinder, and grind to a required fineness at a speed of not higher than 250 kg / h, to obtain an intermediate material; Step 4, uniformly disperse the intermediate material and the acrylic slurry in a reaction kettle, and then add a thermochromic capsule to continue stirring and uniformly disperse, to obtain an ink precursor; Step 5, uniformly mix the remaining polyvinyl butyral slurry, the remaining deionized water, and the remaining cosolvent to obtain an adjusting liquid, and add the adjusting liquid into the ink precursor to adjust the color concentration and viscosity, and then filter to obtain the anti-settling inorganic pigment variable color anti-counterfeiting printing ink. The three fillers are mismatched by controlling the particle sizes, and are preliminarily coated by the polyvinyl butyral slurry, and are intensively suspended by low-speed grinding of the organic bentonite, and are secondarily coated by adding the acrylic slurry and the thermochromic capsule, and the remaining polyvinyl butyral slurry and the cosolvent are used to adjust the viscosity, so that the ink has the properties of long-term anti-settling and high anti-counterfeiting performance.

2. The preparation method of the anti-settling inorganic pigment variable color anti-counterfeiting printing ink according to claim 1, characterized in that, The raw materials of the ink comprise, in percentage by weight: 12%-18% water-soluble resin, 15%-30% deionized water, 10%-15% cosolvent, 10%-15% thermochromic capsule, 8%-15% inorganic pigment, 25%-35% filler, and 2%-4% organic bentonite; wherein the water-soluble resin comprises water-soluble polyvinyl butyral and water-based acrylic emulsion, and the filler comprises titanium dioxide, calcium carbonate, and talc.

3. The preparation method of the anti-settling inorganic pigment variable color anti-counterfeiting printing ink according to claim 2, characterized in that, The mass ratio of the water-soluble polyvinyl butyral to the water-based acrylic emulsion is (2-4):(5-7).

4. The preparation method of the anti-settling inorganic pigment variable color anti-counterfeiting printing ink according to claim 2, characterized in that, The mass ratio of the titanium dioxide to the calcium carbonate to the talc is (5-3):(1-2):

1.

5. The method for preparing the anti-settling inorganic pigment variable color anti- counterfeiting printing ink according to claim 1 or 2, characterized in that, The inorganic pigment comprises iron oxide yellow and iron oxide red.

6. The method of preparing a non-sedimenting inorganic pigment variable color forgery-resistant printing ink according to claim 5, characterized in that, The mass ratio of the iron oxide yellow to the iron oxide red is 1:

1.

7. The method for preparing the anti-settling inorganic pigment variable color anti- counterfeit printing ink according to claim 1 or 2, characterized in that, The cosolvent is a combination of one or more of ethanol, isopropyl alcohol, and n-propanol.

8. The method of preparing the anti-settling inorganic pigment variable color security printing ink according to claim 1, characterized in that, In steps 1 and 5, the mass ratio of the cosolvent is (7-9):(1-3), and the mass ratio of the water-soluble polyvinyl butyral is (7-9):(1-3).

9. The method of producing the anti-settling inorganic pigment variable color security printing ink according to claim 1, characterized by, In steps 3 and 5, the mass ratio of the deionized water is (7-9):(1-3).

10. An anti-settling inorganic pigment variable color anti-counterfeiting printing ink prepared by the method of any one of claims 1-9.

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