CN109575680A - Nano-magnetic ink and its preparation method and application - Google Patents

Abstract

The present invention relates to a kind of nano-magnetic ink and its preparation method and application, the ink is characterized in that, it is made of the raw material containing following components: carbon nano-tube magnetic pigment 12.5-60 parts by weight, aqueous polyurethane 10-35 parts by weight, methacrylate 5-20 parts by weight, acrylate 5-25 parts by weight and initiator 1-5 parts by weight；Wherein, the carbon nano-tube magnetic pigment uses the raw material containing following components to be made: 0.5-5 parts of modified carbon nano-tube, 5-20 parts of Iron(III) chloride hexahydrate, 3-15 parts of sodium acetate and ethylenediamine 4-20 parts by weight.The ink can solve the disadvantages of unstable traditional magnetic ink and easy precipitating, obtain a kind of environment-friendly type superparamagnetism ink of carbon nanotube base, expand the performance advantage of magnetic ink, have broad application prospects.

Description

Nano magnetic ink and preparation method and application thereof

technical field

The invention relates to the technical field of packaging and printing materials, in particular to a nano-magnetic ink and a preparation method and application thereof.

Background technique

Because water-based ink does not contain or contain trace amounts of volatile organic compounds (VOC), it has no adverse effects on the health of workers during the printing process, hardly pollutes the atmosphere, and reduces the toxicity of substances remaining on the surface of the printed matter, eliminating production. Therefore, water-based ink is one of the most promising green printing materials. It has been widely used in cigarette packs, wine, food, beverages, medicines and children's toys. The printing quality is strict. on the packaging print. Special printing ink is a kind of ink with anti-counterfeiting function and special function, including magnetic ink, conductive ink, temperature change ink, pressure sensitive ink, metal ink, etc. They are not only widely used in the packaging and printing of high-end commodities, but also in It has been concerned and applied in industries such as currency, securities, contract insurance, and microelectronics manufacturing. At present, the development of water-based inks and existing functional special printing inks (including magnetic inks) still has the following main problems: (1) There are few varieties of water-based inks and high production costs, especially the varieties of special printing water-based inks are single or basically no. , hindering the wide application of water-based inks in the printing industry; (2) the drying performance of water-based inks is poor, it is difficult to adapt to the needs of high-speed printing, which hinders the process of green packaging printing; (3) The existing special printing inks are mainly solvent-based and have high pollution. , the harm is great, the preparation process is difficult to control, and the functional realization is not obvious.

Water-based magnetic inks were prepared using carbon nanotubes (CNTs) and magnetic carbon nanotubes as pigments or functional fillers. Carbon nanotubes have the simplest chemical composition and atomic bonding state, but show excellent physical, chemical, electrical and thermal properties. The basic structure of hexagonal grids in carbon nanotubes is C=C covalent bonds. The orderly arrangement along the axis of CNTs constitutes a closed space structure, which belongs to one-dimensional nanomaterials and possesses excellent mechanical properties, electrical properties, thermal properties, hydrogen storage properties, wave absorption properties and optical properties. It is one of the nanomaterials with the most research potential and application prospects at present. It is one of the hotspots in the current composite materials research to apply it as filler or modifier to improve the mechanical properties of traditional chemical products or give them special properties. It has been reported that CNT/polymer composites have great potential applications in new materials for conducting/storing electricity (such as conductive paper, electrodes, capacitors, lithium batteries, etc.).

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is: the traditional magnetic ink has shortcomings such as unstable magnetic properties and easy precipitation, and the environmental protection needs to be improved.

The purpose of the present invention is to solve the problems of environmental protection and magnetic instability of the current magnetic ink. The invention adopts multi-walled carbon nanotubes as the matrix of the magnetic nano-pigment, assists with nano-iron tetroxide particles to prepare composite nano-magnetic pigment, and then prepares environmental protection with water-based polyurethane/polyacrylate binder resin and related water-soluble additives. Type nanometer superparamagnetic ink. Provided is a preparation method of a water-based superparamagnetic ink with a simple process and a friendly environment.

In order to solve the above-mentioned technical problems, the present invention adopts a hydrothermal method to reduce iron elements from hydrates to prepare nano-iron tetroxide particles, which are grown on the surface of carbon nanotubes in situ, and then mixed with water-based polyurethane/polyacrylate. The binder resin, environment-friendly additives, etc. are mixed, and the environment-friendly ink with superparamagnetic properties is prepared by the ball milling method.

Specifically, for the deficiencies in the prior art, the present invention provides the following technical solutions:

A kind of nanometer magnetic ink is characterized in that, adopts the raw material that contains following component to make:

12.5-60 parts by weight of carbon nanotube magnetic pigment, 10-35 parts by weight of water-based polyurethane, 5-20 parts by weight of methacrylate, 5-25 parts by weight of acrylate and 1-5 parts by weight of initiator;

Wherein, the carbon nanotube magnetic pigment is made of raw materials containing the following components:

0.5-5 parts of modified carbon nanotubes, 5-20 parts of ferric chloride hexahydrate, 3-15 parts of sodium acetate and 4-20 parts by weight of ethylenediamine.

Preferably, in the above magnetic ink, the carbon nano-magnetic pigment accounts for 25-55% of the magnetic ink, preferably 30-45%, and the water-based polyurethane accounts for 15-50% of the magnetic ink, preferably 20-40% %.

Preferably, in the above magnetic ink, the mass fraction of methacrylate in the magnetic ink is 8-20%, and the mass fraction of acrylate in the magnetic ink is 8-20%.

Preferably, in the above magnetic ink, the raw material further includes a solvent, and the solvent is 5-40 parts by weight.

Preferably, in the above magnetic ink, the solvent is deionized water.

Preferably, in the above magnetic ink, the modified carbon nanotubes are prepared by a method comprising the following steps:

The carbon nanotubes are added into nitric acid and modified to obtain modified carbon nanotubes; wherein, the weight ratio of the nitric acid to the carbon nanotubes is: (5-12): (1-3.5).

Preferably, in the above magnetic ink, the methacrylate is selected from one or more of methyl methacrylate or ethyl methacrylate.

Preferably, in the above magnetic ink, the acrylate is selected from one or more of methyl acrylate, butyl acrylate, acrylic acid, n-butyl acrylate, 2-hydroxyethyl acrylate or ethyl methacrylate.

Preferably, in the above magnetic ink, the acrylates include methyl acrylate and butyl acrylate, the methyl acrylate is 3-13 parts by weight, and the butyl acrylate is 2-12 parts by weight.

Preferably, in the above magnetic ink, the initiator is selected from one or more of azobisisobutyronitrile and potassium persulfate.

Preferably, in the above magnetic ink, the raw material further includes 1-8 parts by weight of an emulsifier selected from polyoxyethylene octyl phenol ether-10, sodium dodecyl sulfate or monolaurin one or two or more.

Preferably, in the above magnetic ink, the raw material further includes 1-8 parts by weight of liquid paraffin.

Preferably, in the above magnetic ink, the raw material further includes 1-8 parts by weight of a defoamer selected from one or both of polysiloxane, GP-type defoamer or GPE-type defoamer more than one species.

The present invention also provides the preparation method of above-mentioned nanometer magnetic ink, it is characterized in that, comprises the following steps:

(1) adding modified carbon nanotubes, ferric chloride hexahydrate, sodium acetate and ethylenediamine into the reactor, and carrying out a hydrothermal reaction to obtain a carbon nanotube magnetic pigment;

(2) mixing water-based polyurethane, methacrylate and acrylate, adding an initiator, and carrying out a polymerization reaction;

(3) adding carbon nanotube magnetic pigment to the product obtained in step (2), and continuing the reaction to obtain the nano magnetic ink.

Preferably, in the above preparation method, the modified carbon nanotubes in step (1) are prepared by a method comprising the following steps:

The carbon nanotubes are added to the concentrated nitric acid solution, diluted with water, dispersed evenly, and then refluxed in a cooling and refluxing device to obtain modified carbon nanotubes.

Preferably, in the above preparation method, the temperature of the reflux operation is 40-70° C. and the time is 8-16 hours.

Preferably, in the above preparation method, the dispersion of the carbon nanotubes is carried out under ultrasonic conditions, and the ultrasonic conditions are: ultrasonic waves at 200-300 W for 30-60 min.

Preferably, in the above preparation method, in step (1), before adding the modified carbon nanotubes to the reaction kettle, the modified carbon nanotubes are added to a dispersant for dispersion; the dispersant is selected from ethylene glycol.

Preferably, in the above preparation method, the dispersant is 18-35 parts by weight.

Preferably, in the above preparation method, the dispersion conditions of the carbon nanotubes in the first dispersant are: ultrasonic for 30-60 min in an ice bath environment.

Preferably, in the above preparation method, the particle size of the ferric chloride hexahydrate is 1 μm-1 mm, and the particle size of the sodium acetate is 1 μm-1 mm.

Preferably, in the above preparation method, the initiator is 1-5 parts by weight.

Preferably, in the above preparation method, the temperature of the hydrothermal reaction is 180-250°C, and the time is 4-6h.

Preferably, in the above preparation method, the temperature of the mixing process in step (2) is 50-70° C. and the time is 15-30 min.

Preferably, in the above preparation method, after the initiator is added in the step (2), the process of adding an emulsifier is also included.

Preferably, in the above preparation method, the step (2) further includes a process of adding a solvent, and the solvent is preferably deionized water.

Preferably, in the above preparation method, the temperature of the polymerization reaction in step (2) is 50-70° C., and the time is 2-5 h.

Preferably, in the above preparation method, the reaction temperature in step (3) is 50-70° C., and the time is 1.5-3 h.

Preferably, in the above preparation method, after the reaction described in step (3), the following steps are also included:

Add liquid paraffin and polysiloxane, and after shearing and mixing, magnetic ink is obtained.

The present invention also provides a magnetic ink film, which is characterized in that it is prepared from the above magnetic ink.

The present invention also provides the application of the above-mentioned magnetic ink or the above-mentioned magnetic ink film in the field of ink.

The advantages of the present invention are: using CNT as the nano-filler of the water-based conductive ink, solving the shortcomings of magnetic instability and easy precipitation in the traditional magnetic ink, preparing a carbon nanotube-based environment-friendly superparamagnetic ink, and expanding the performance of the magnetic ink Advantage. It is proposed to adopt the technical scheme of grafting iron oxide nanoparticles on CNTs to endow CNTs with magnetic properties, and the modified iron oxides increase the specific surface area of CNTs, and endow their surface with more functional groups, forming The tentacle-like structure enhances its dispersion stability in the continuous phase medium.

Description of drawings

1 is a scanning electron microscope image of the nanotube magnetic pigment obtained in Example 1, with a magnification of 90,000 times.

Figure 2-a and Figure 2-b are the shape diagrams of the nanotube magnetic pigment obtained in Example 1 under the adsorption of a circular magnet and a special-shaped magnet, respectively.

Figure 3-a is a hysteresis loop of the magnetic ink film obtained in Example 1 under an external magnetic field; Figure 3-b is a diagram showing the adsorption effect of the magnetic ink film obtained in Example 1 on a magnet.

Detailed ways

In order to solve the problems of unstable magnetic properties and easy precipitation of traditional inks, the present invention provides a superparamagnetic ink and a preparation method and application thereof.

In a preferred embodiment, the ink is prepared from the following raw materials and proportions (in parts by weight): 0.5-5 parts of modified (purified) carbon nanotubes, 18-35 parts of ethylene glycol, Ferric chloride hexahydrate (FeCl ₃ 6H ₂ O) 5-20 parts, ethylenediamine 4-20 parts, sodium acetate 3-15 parts, ethanol 30-100 parts, deionized water 40-120 parts, water-based polyurethane 10-35 parts, methyl methacrylate 5-20 parts, methyl acrylate 3-13 parts, butyl acrylate 2-12 parts, azobisisobutyronitrile 1-5 parts, polyoxyethylene octyl phenol ether- 10 (OP-10) 1-8 parts, liquid paraffin 1-8 parts, polysiloxane 1-8 parts. Wherein, the modified (purified) carbon nanotubes are obtained by modifying multi-walled carbon nanotubes in concentrated nitric acid, and the weight ratio of the concentrated nitric acid to the multi-walled carbon nanotubes is (5-12): (1-3.5 ).

In another preferred embodiment, the specific operation steps of the preparation method of the magnetic ink are as follows:

(1) Weigh a quantitative amount of multi-walled carbon nanotubes (MWCNTs) into a 100 mL beaker, add concentrated nitric acid solution, add deionized water to dilute, and place it in a 250W ultrasonic cleaner for 30 minutes. The MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs;

(2) Weigh the quantitatively purified MWCNTs into a beaker, add ethylene glycol as a dispersant, then seal the mouth of the beaker with a plastic film, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment;

(3) Grind FeCl ₃ ·6H ₂ O into powder in an agate mortar, weigh NaAc powder, add it to the dry inner tank of the reactor at the same time, then add ethylenediamine to it to disperse the powder, stir and mix evenly ;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the precipitate after the centrifugation, and use deionized water and anhydrous ethanol to remove the precipitate. Repeated cleaning for several times until the cleaned supernatant was clean and transparent, and finally the cleaned precipitate was placed in a 50°C oven to dry for 24 hours to obtain a MWCNTs composite with nanoparticles grafted on the surface;

(6) Add water-based polyurethane, methyl methacrylate, methyl acrylate, and butyl acrylate successively to a three-necked flask with a stirring device, heat, stir and mix at 60° C. After 15 minutes of reaction, add azobisisobutyl Nitrile and OP-10, after reacting for 3 hours, add the product prepared in (5), and continue to heat and react for 2 hours under the same process parameters;

(7) Mix the product in (6) with liquid paraffin and polysiloxane, stir at room temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and sieve the mixture through a 200-mesh sieve, Take the mixture under the sieve, which is the magnetic ink; then pour the mixture into a polytetrafluoroethylene mold respectively, and place the mixture and the polytetrafluoroethylene mold in a constant temperature drying oven at 50°C for 12 hours to dry to obtain a magnetic ink film.

The magnetic nano ink of the present invention refers to: the nano here refers to the composite of carbon nanotubes grafted with ferric oxide, and at least one dimension is in the nano range, so the nano refers to the ferric oxide A composite of carbon nanotubes, which is also a pigment in the ink.

The GP type antifoaming agent of the present invention refers to polyoxypropylene glyceryl ether, and the GPE type antifoaming agent refers to polyoxypropylene polyoxyethylene glycerol ether.

The thermochromic VO ₂ nanomaterial of the present invention and its preparation method and application will be further described below through specific examples.

In the following examples, the information of each reagent and instrument used is shown in the following table:

Table 1 Information on reagents and instruments used in the examples of the present invention

Example 1

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 2 nanometer magnetic ink raw material ratio table (parts by weight)

(1) Weigh 3 parts of multi-walled carbon nanotubes (MWCNTs) into a 100 mL beaker, add 10 parts of concentrated nitric acid solution, add 10 parts of deionized water for dilution, place it in a 250W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 1 part of purified MWCNTs into a beaker, add 25 parts of ethylene glycol as a dispersant, then seal the mouth of the beaker with a plastic film, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) 10 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 5 parts of NaAc powder were weighed and added to the dry inner liner of the reactor at the same time, and then 8 parts of ethylenediamine were added to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 40 parts of deionized water and 40 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 20 parts of water-based polyurethane, 8 parts of methyl methacrylate, 5 parts of methyl acrylate, and 5 parts of butyl acrylate were successively added to a three-necked flask with a stirring device, heated, stirred and mixed at 60° C., and reacted for 15 minutes Then, add a mixture of 2 parts of azobisisobutyronitrile, 2 parts of OP-10, and 10 parts of deionized water, after 3 hours of reaction, add the product prepared in (5), and continue to heat and react for 2 hours under the same process parameters ;

(7) Mix the product in (6) with 2 parts of liquid paraffin and 2 parts of polysiloxane, stir at normal temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The scanning electron microscope image of the magnetic pigment obtained in this example is shown in Figure 1. It can be seen from the figure that the nano-iron tetroxide particles have been successfully grafted on the surface of carbon nanotubes to form clusters, which endow carbon nanotubes with magnetism. At the same time, Due to the large specific surface area of nanospheres, the dense ferric oxide also greatly increases the specific surface area of carbon nanotubes.

A round magnet and a special-shaped magnet are placed under the beaker containing the magnetic pigment obtained in this example, and the shapes of the magnetic pigment under the adsorption of the magnet are shown in Figures 2-a and 2-b, respectively. It can be seen from the figure that the magnetic pigment forms a circular figure under the adsorption of the circular magnet, and the special-shaped figure formed under the adsorption of the special-shaped magnet. It can be seen that the prepared magnetic pigment can form the same shape as the magnet under the action of the magnetic field. Under the action, the shape can be changed arbitrarily, and the performance is excellent.

Figure 3-a shows the hysteresis loop of the magnetic ink film prepared in Example 1 under the action of an external magnetic field. When the strength of the applied magnetic field is zero, the magnetic properties of the ink film are also zero. At the same time, it can be seen from the curve in the figure that the maximum superparamagnetic strength of the ink film formed by the magnetic ink is about 1.5 emu/g, so the magnetic ink prepared by the invention has excellent magnetic properties. Figure 3-b shows that the ink film formed after the magnetic ink is dried can be adsorbed by the magnet and has a good magnetic effect.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink ranged from 230-450mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 34s.

Example 2

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink

Table 3 nanometer magnetic ink raw material ratio table (parts by weight)

(1) Weigh 1 part of multi-walled carbon nanotubes (MWCNTs) into a 100mL beaker, add 5 parts of concentrated nitric acid solution, add 5 parts of deionized water to dilute, place it in a 250W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 0.5 parts of purified MWCNTs into a beaker, add 18 parts of ethylene glycol as a dispersant, then seal the mouth of the beaker with a plastic film, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) 5 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 3 parts of NaAc powder were weighed and added to the dry inner liner of the reactor at the same time, and then 4 parts of ethylenediamine were added to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 30 parts of deionized water and 30 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 12 parts of water-based polyurethane, 5 parts of methyl methacrylate, 3 parts of methyl acrylate, and 2 parts of butyl acrylate were successively added to a three-necked flask with a stirring device, heated, stirred and mixed at 60° C., and reacted for 15 minutes Then, add a mixture of 1 part of azobisisobutyronitrile, 1 part of OP-10 and 5 parts of deionized water, after 3 hours of reaction, add the product prepared in (5), and continue to heat and react for 2 hours under the same process parameters ;

(7) Mix the product in (6) with 1 part of liquid paraffin and 1 part of polysiloxane, stir at normal temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in Example 2 were tested by the same method as in Example 1, and the results showed that the superparamagnetic strength was 2.0 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink ranged from 210-385mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 53s.

Example 3

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 4 nanometer magnetic ink raw material ratio table (parts by weight)

(1) Weigh 3.5 parts of multi-walled carbon nanotubes (MWCNTs) into a 100mL beaker, add 12 parts of concentrated nitric acid solution, add 12 parts of deionized water to dilute, place it in a 250W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 2 parts of purified MWCNTs into a beaker, add 28 parts of ethylene glycol as a dispersant, then seal the mouth of the beaker with a plastic film, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) 13 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 7 parts of NaAc powder were weighed and added to the dry inner liner of the reactor at the same time, and then 10 parts of ethylenediamine were added to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 50 parts of deionized water and 50 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 25 parts of water-based polyurethane, 10 parts of methyl methacrylate, 8 parts of methyl acrylate, and 8 parts of butyl acrylate were successively added to the three-necked flask with stirring device, heated, stirred and mixed at 60° C., and reacted for 15 minutes Then, add a mixture of 3 parts of azobisisobutyronitrile, 3 parts of OP-10, and 8 parts of deionized water, after 3 hours of reaction, add the product prepared in (5), and continue to heat and react for 2 hours under the same process parameters ;

(7) Mix the product in (6) with 2.5 parts of liquid paraffin and 2.5 parts of polysiloxane, stir at room temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in Example 3 were detected by the same method as in Example 1, and the results showed that the superparamagnetic strength was 1.7 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink was in the range of 389-562mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 28s.

Example 4

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 5 nanometer magnetic ink raw material ratio table (weight parts)

(1) Weigh 3 parts of multi-walled carbon nanotubes (MWCNTs) into a 100mL beaker, add 10 parts of concentrated nitric acid solution, add 10 parts of deionized water to dilute, place it in a 200W ultrasonic cleaner for 60 minutes and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 70 °C for 8 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 3 parts of purified MWCNTs into a beaker, add 30 parts of ethylene glycol as a dispersant, then use a plastic film to seal the mouth of the beaker, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) 16 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 10 parts of NaAc powder were weighed and added to the dry inner liner of the reactor, and then 15 parts of ethylenediamine were added to Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a constant temperature oven at 180°C for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 70 parts of deionized water and 70 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 30 parts of water-based polyurethane, 15 parts of methyl methacrylate, 10 parts of methyl acrylate, and 10 parts of butyl acrylate were successively added to the three-necked flask with stirring device, heated, stirred and mixed at 50° C., and reacted for 30 minutes Then, add a mixture of 4 parts of azobisisobutyronitrile, 5 parts of OP-10 and 20 parts of deionized water, after 5 hours of reaction, add the product prepared in (5), and continue to heat and react for 1.5 hours under the same process parameters ;

(7) Mix the product in (6) with 5 parts of liquid paraffin and 5 parts of polysiloxane, stir at normal temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in Example 4 were tested by the same method as in Example 1, and the results showed that the superparamagnetic strength was 3.2 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink ranged from 371-532mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 28s.

Example 5

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 6 nanometer magnetic ink raw material ratio table (weight parts)

(1) Weigh 3 parts of multi-walled carbon nanotubes (MWCNTs) into a 100 mL beaker, add 10 parts of concentrated nitric acid solution, add 10 parts of deionized water to dilute, place it in a 300W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 40 °C for 16 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 5 parts of purified MWCNTs into a beaker, add 35 parts of ethylene glycol as a dispersant, then use a plastic film to seal the mouth of the beaker, place it in an ultrasonic cleaner, and sonicate for 60 minutes in an ice bath environment ;

(3) 20 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 15 parts of NaAc powder were weighed and added to the dry inner liner of the reactor at the same time, and then 20 parts of ethylenediamine were added to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 250°C constant temperature oven for heating, keep the constant temperature for 6 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 75 parts of deionized water and 75 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 35 parts of water-based polyurethane, 20 parts of methyl methacrylate, 13 parts of methyl acrylate, and 12 parts of butyl acrylate were successively added to the three-necked flask with stirring device, heated, stirred and mixed at 70° C., and reacted for 15 minutes Then, add a mixture of 7 parts of azobisisobutyronitrile, 8 parts of sodium dodecyl sulfate, 35 parts of deionized water, after 2 hours of reaction, add the product prepared in (5), continue heating under the same process parameters reaction for 3 hours;

(7) Mix the product in (6) with 8 parts of liquid paraffin and 8 parts of polysiloxane, stir at normal temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in Example 5 were tested by the same method as in Example 1, and the results showed that the superparamagnetic strength was 2.8 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink was in the range of 285-320mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 48s.

Example 6

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 7 nanometer magnetic ink raw material ratio table (parts by weight)

(1) Weigh 3 parts of multi-walled carbon nanotubes (MWCNTs) into a 100 mL beaker, add 10 parts of concentrated nitric acid solution, add 10 parts of deionized water for dilution, place it in a 250W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 1 part of purified MWCNTs into a beaker, add 25 parts of ethylene glycol as a dispersant, then seal the mouth of the beaker with a plastic film, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) Grind 8 parts of FeCl ₃ ·6H ₂ O into powder in an agate mortar, and weigh 4 parts of NaAc powder, add it to the dry inner tank of the reactor at the same time, and then add 8 parts of ethylenediamine to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 40 parts of deionized water and 40 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain a MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 35 parts of water-based polyurethane, 8 parts of methyl methacrylate, 5 parts of methyl acrylate, and 5 parts of butyl acrylate were successively added to the three-necked flask with stirring device, heated, stirred and mixed at 60° C., and reacted for 15 minutes Then, add a mixture of 2 parts of azobisisobutyronitrile, 2 parts of potassium persulfate, and 10 parts of deionized water, after 3 hours of reaction, add the product prepared in (5), and continue to heat and react for 2 hours under the same process parameters ;

(7) Mix the product in (6) with 2 parts of liquid paraffin and 2 parts of polysiloxane, stir at normal temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in Example 6 were tested by the same method as in Example 1, and the results showed that the superparamagnetic strength was 3.4 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink ranged from 459-603mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 21s.

Example 7

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 8 nanometer magnetic ink raw material ratio table (weight parts)

(1) Weigh 3 parts of multi-walled carbon nanotubes (MWCNTs) into a 100 mL beaker, add 10 parts of concentrated nitric acid solution, add 10 parts of deionized water for dilution, place it in a 250W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 3 parts of purified MWCNTs into a beaker, add 25 parts of ethylene glycol as a dispersant, then use a plastic film to seal the mouth of the beaker, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) 16 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 10 parts of NaAc powder were weighed and added to the dry inner liner of the reactor at the same time, and then 8 parts of ethylenediamine were added to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 40 parts of deionized water and 40 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 12 parts of water-based polyurethane, 8 parts of methyl methacrylate, 5 parts of methyl acrylate, and 5 parts of butyl acrylate were successively added to a three-necked flask with a stirring device, heated, stirred and mixed at 60° C., and reacted for 15 minutes Then, add a mixture of 2 parts of azobisisobutyronitrile, 2 parts of OP-10, and 10 parts of deionized water, after 3 hours of reaction, add the product prepared in (5), and continue to heat and react for 2 hours under the same process parameters ;

(7) Mix the product in (6) with 2 parts of liquid paraffin and 2 parts of polysiloxane, stir at room temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in Example 7 were detected by the same method as in Example 1, and the results showed that the superparamagnetic strength was 3.8 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink ranged from 458-612mPa·s.

The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 19s.

Comparative ratio

In this example, the raw materials in parts by weight in the following table are used to prepare magnetic ink.

Table 9 nanometer magnetic ink raw material ratio table (parts by weight)

(1) Weigh 3 parts of multi-walled carbon nanotubes (MWCNTs) into a 100 mL beaker, add 10 parts of concentrated nitric acid solution, add 10 parts of deionized water for dilution, place it in a 250W ultrasonic cleaner for 30 minutes, and disperse After homogenization, the MWCNTs were placed in a cooling reflux device and refluxed at 60 °C for 12 hours to prepare purified MWCNTs; wherein, each portion represented 1 g;

(2) Weigh 0.5 parts of purified MWCNTs into a beaker, add 25 parts of ethylene glycol as a dispersant, then seal the mouth of the beaker with a plastic film, place it in an ultrasonic cleaner, and sonicate for 30 minutes in an ice bath environment ;

(3) 3 parts of FeCl ₃ ·6H ₂ O were ground into powder in an agate mortar, and 2 parts of NaAc powder were weighed and added to the dry inner liner of the reactor at the same time, and then 4 parts of ethylenediamine were added to it. Disperse the powder, stir and mix evenly;

(4) pour the ultrasonically dispersed uniform mixture in (2) into the inner tank of the reactor, stir and mix uniformly;

(5) place the reaction kettle in a 200°C constant temperature oven for heating, keep the constant temperature for 4 hours, then take out the reaction kettle, centrifuge the liquid with a centrifuge, take the centrifuged sediment, use 40 parts of deionized water and 40 parts of anhydrous The precipitate was repeatedly washed with ethanol for several times until the washed supernatant was clean and transparent. Finally, the washed precipitate was placed in a 50 °C oven to dry for 24 hours to obtain the MWCNTs composite with nanoparticles grafted on the surface, namely Carbon nanotube magnetic pigments;

(6) 20 parts of water-based polyurethane, 5 parts of methyl acrylate and 5 parts of butyl acrylate were successively added to a three-necked flask with a stirring device, heated, stirred and mixed at 60° C. After 15 minutes of reaction, 2 parts of azodicarbonate were added. A mixture of isobutyronitrile, 2 parts of OP-10 and 10 parts of deionized water, after 3 hours of reaction, the product prepared in (5) was added, and the heating reaction was continued for 2 hours under the same process parameters;

(7) Mix the product in (6) with 2 parts of liquid paraffin and 2 parts of polysiloxane, stir at normal temperature for 10 minutes, then shear and mix for 1 hour under the action of a shear emulsifier, and pass the mixture through a 200-mesh sieve The mesh is sieved, and the mixture under the sieve is the magnetic ink; then the mixture is poured into a polytetrafluoroethylene mold respectively, and the mixture and the polytetrafluoroethylene mold are placed in a constant temperature drying box at 50 ° C to dry for 12 hours to obtain Magnetic ink film.

The magnetic properties of the magnetic ink film obtained in the comparative example were detected by the same method as in Example 1, and the results showed that the superparamagnetic strength was 0.6 emu/g.

Ink viscosity/curing speed: The viscosity of the ink was tested by the American Brookfield DV-I viscometer, and the viscosity value of the ink ranged from 20-80mPa·s. The viscosity of the ink is too small to be suitable for common printing processes. The ink was coated on a glass slide, dried and cured in an oven at 50°C, and the average curing time required was 5 min. The required curing time is longer, the ink drying speed is slow, and the printing speed is reduced.

To sum up, the present invention prepares a carbon nanotube-based environment-friendly superparamagnetic ink, which solves the shortcomings of traditional magnetic ink such as magnetic instability and easy precipitation, expands the performance advantages of the magnetic ink, and has broad application. prospect.

Claims (18)

1. a kind of nano-magnetic ink, which is characterized in that be made of the raw material containing following components:

Carbon nano-tube magnetic pigment 12.5-60 parts by weight, aqueous polyurethane 10-35 parts by weight, methacrylate 5-20 weight Part, acrylate 5-25 parts by weight and initiator 1-5 parts by weight；

Wherein, the carbon nano-tube magnetic pigment uses the raw material containing following components to be made:

0.5-5 parts of modified carbon nano-tube, 5-20 parts of Iron(III) chloride hexahydrate, 3-15 parts of sodium acetate and ethylenediamine 4-20 parts by weight.

2. magnetic ink according to claim 1, wherein the mass fraction that carbon nano-magnetic pigment accounts for magnetic ink is 25- 55%, preferably 30-45%, the mass fraction that aqueous polyurethane accounts for magnetic ink is 15-50%, preferably 20-40%.

3. magnetic ink according to claim 1 or claim 2, wherein the mass fraction that methacrylate accounts for magnetic ink is 8- 20%, the mass fraction that acrylate accounts for magnetic ink is 8-20%.

4. any one of -3 magnetic ink according to claim 1, wherein the raw material further includes solvent, and the solvent is 5- 40 parts by weight.

5. any one of -4 ink according to claim 1, wherein method of the modified carbon nano-tube by including the following steps It is prepared:

Carbon nanotube is added in nitric acid, processing is modified, obtains modified carbon nano-tube；Wherein, the nitric acid and carbon nanometer The weight ratio of pipe are as follows: (5-12): (1-3.5).

6. any one of -5 ink according to claim 1, wherein the methacrylate be selected from methyl methacrylate or The one or two of ethyl methacrylate.

7. any one of -6 ink according to claim 1, wherein the acrylate is selected from methyl acrylate, acrylic acid fourth Ester, acrylic acid, n-butyl acrylate, 2-Hydroxy ethyl acrylate or ethyl methacrylate one or more.

8. any one of -7 ink according to claim 1, wherein the raw material further includes emulsifier 1-8 parts by weight, the cream Agent is selected from the one or more of polyoxethylene octylphenyl phenol ether -10, ten disulfo sodium sulphate or lauric monoglyceride.

9. any one of -8 ink according to claim 1, wherein the raw material further includes liquid paraffin 1-8 parts by weight.

10. any one of -9 ink according to claim 1, wherein the raw material further includes defoaming agent 1-8 parts by weight, described Defoaming agent is selected from the one or more of polysiloxanes, GP type defoaming agent or GPE type defoaming agent.

11. the preparation method of nano-magnetic ink described in claim 1, which is characterized in that include the following steps:

(1) modified carbon nano-tube, Iron(III) chloride hexahydrate, sodium acetate and ethylenediamine are added in reaction kettle, carry out hydro-thermal reaction, Obtain carbon nano-tube magnetic pigment；

(2) by aqueous polyurethane, methacrylate and crylic acid ester mixture, initiator is added, carries out polymerization reaction；

(3) carbon nano-tube magnetic pigment is added into step (2) products therefrom, the nano-magnetic oil is obtained after the reaction was continued Ink.

12. preparation method according to claim 12, wherein modified carbon nano-tube described in step (1) is by including following steps Rapid method is prepared:

Carbon nanotube is added in concentrated nitric acid solution, adds and is diluted with water, carry out reflux behaviour in cooling and reflux device after being uniformly dispersed Make, obtains modified carbon nano-tube.

13. 1 or 12 preparation method according to claim 1, wherein in step (1), the modified carbon nano-tube is being added instead Before answering kettle, first it is added in dispersing agent and is dispersed.

14. any one of 1-13 preparation method according to claim 1, wherein the temperature of the hydro-thermal reaction is 180-250 ℃。

15. any one of 1-14 preparation method according to claim 1, wherein the temperature of polymerization reaction described in step (2) is 50-70℃。

16. any one of 1-15 preparation method according to claim 1, wherein reaction temperature described in step (3) is 50-70 ℃。

17. a kind of magnetism ink film, which is characterized in that be prepared by any one of the claim 1-10 magnetic ink.

18. magnetism ink film answering in ink area described in any one of the claim 1-10 magnetic ink or claim 17 With.