Preparation method of high-stability self-crosslinking colloid photon ink for textile inkjet printing

Abstract

The invention discloses a preparation method of high-stability self-crosslinking colloid photon ink for inkjet printing of textiles, and provides a strategy of combining surface carboxylation hard core-soft shell type nano microspheres and fabric surface polymer induction. A reversible addition-fragmentation chain transfer polymerization (RAFT) emulsion polymerization method with high monomer conversion rate and good controllability is adopted, and the surface carboxylated hard core-soft shell type nano microspheres are prepared through a one-pot method. On the basis, a colloidal photon ink system is constructed by compounding a specific functional aid, so that the colloidal photon ink not only can maintain a stable state for 12 months under conventional storage conditions, but also can effectively resist a microsphere agglomeration phenomenon caused by high shear force and temperature shock in an ink-jet printing process, and the problem of nozzle blockage is avoided. According to the technical scheme, on the premise that the low solid content of the system is ensured, the color development saturation and the structural color stability are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of structural color and textile inkjet printing, and particularly relates to a preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing. Background Art

[0002] As an efficient and environmentally friendly fabric patterning processing method, textile inkjet printing technology can achieve accurate reproduction of pattern design and rapid response to mass production, and has gradually become the development direction of new technologies in the textile dyeing and finishing industry. As one of the core consumables for inkjet printing, the performance of the ink directly determines the visual effects such as color accuracy and contour clarity of textile printed patterns. Currently, the mainstream inkjet printing inks are mostly dye- or pigment-based, mainly relying on pigment color (chemical color) to achieve color, that is, presenting color by selectively absorbing incident light of specific wavelengths. Although the existing dye- and pigment-based digital printing ink technologies are relatively mature, there are still technical bottlenecks in terms of color expressiveness and durability.

[0003] Inspired by biological micro-nano structures, photonic crystals, as an optical material with a periodic arrangement of refractive indices at the sub-micron scale, have been proposed. Due to their unique light regulation characteristics, they are currently widely used in many fields such as displays, sensors, and anti-counterfeiting. Different from the chemical color development mechanism of conventional pigments / dyes, the structural color generation technology of photonic crystals stems from their induced Bragg diffraction and photonic bandgap effects. By precisely controlling the lattice parameters (such as microsphere particle size and arrangement), this technology can not only achieve supersaturated color development but also endow an angle-dependent iridescent effect, making it an ideal material for developing digital printing inks with unique visual effects and excellent durability.

[0004] In recent years, with the development and application of new photonic crystal materials, photonic crystal materials have been designed for digital printing inks and endow different substrates with structural color effects through printing. Among them, the method of constructing photonic crystal structural color with colloidal nano-microspheres as assembly units is being tried in textile inkjet printing in order to obtain structural color patterned fabrics with high resolution, high durability, and iridescent effects.

[0005] Patent CN108442138A discloses a preparation method of a surface-adsorbing dye-type nano-microsphere structure chromogenic ink for digital inkjet printing of textiles. This method uses monodisperse nano-microspheres with a low solid content (5.0 - 10.0 parts by weight) as chromogenic elements, constructs a synergistic stabilization system by introducing functional additives (such as surface tension regulators, pH buffers), and selects hetero-charge dye molecules to be added to the system based on the principle of charge complementarity to improve the chromogenic performance of the structure chromogenic ink. Finally, a digital jet printing system is simulated by a dispensing machine to inkjet print on textiles to form structural colors, eliminating the step of pre-dyeing textiles. This method requires adding hetero-charge dyes to improve color quality, while the overall printability of the colloidal nano-microsphere ink, such as stability, viscosity, rheology, etc., can only meet the printing requirements of the dispensing machine system.

[0006] Patent CN103788770B discloses a colloidal microsphere ink for structural color generation in textile inkjet printing and its application method. This method first formulates a printing ink by combining monodisperse colloidal microspheres with a solid content of 0.5 - 1.5 wt% with a pH regulator, an anionic surfactant, and water, and then prints on the surface of a fabric treated with a water-repellent treatment. Structural colors are generated through self-assembly of the microspheres, having advantages such as ecological environmental protection and material saving. This method does not require additional addition of colorants such as pigments or dyes, but due to the low solid content (0.5 - 1.5 wt%) of the prepared ink, the quality of the structural color after printing is limited and the saturation is low.

[0007] Patent CN101195721A discloses an application method of an emulsion containing monodisperse polymer latex particles in a color inkjet printing ink. This method uses a batch soap-free emulsion polymerization method, mixes 3 monomers with gradually increasing hydrophilicity and disperses them in an aqueous solution containing a pH buffer and an emulsifier for reaction (the reaction time of the system is 10 - 11 h), prepares a microsphere emulsion (the concentration range is 10 - 20 wt%), and then adds it to an inkjet printer for printing. The shell layer of the monodisperse polymer latex particles deforms during the printing process to form a dense honeycomb-like photonic crystal structure. However, on the one hand, the soap-free emulsion polymerization method still selects sodium dodecyl sulfate as an emulsifier, and this surface-adsorbing emulsifier has problems of dissociation and desorption, thus affecting the storage and use stability of the ink; secondly, the formation of the core-shell structure is achieved by the gradual migration of hydrophilic groups to the surface layer, but in some applications that require washing or wet treatment, the hydrophilic shell layer on the surface has problems such as insufficient wet rubbing color fastness, greatly limiting the application of this solution in fields such as textiles.

[0008] Patent CN202210721474 discloses a method for preparing a patterned photonic crystal structure color-producing fabric by an inkjet printing technique. This method uses high-concentration nano-microspheres (dosage 15 - 25 wt%, particle size 150 - 350 nm), adds a high-concentration humectant (dosage 5 - 10 wt%), a dispersant and a series of other reagents to prepare printing ink, and then performs localized inkjet printing on a fabric surface-modified with a special polymer. A relatively stable photonic crystal structure is formed through heat treatment. However, adding a surfactant in the above method can only maintain the stability of the high-concentration nano-microsphere dispersion during storage at room temperature, but it is easily affected by shear force, temperature, etc. during spraying, causing the carboxyl groups based on physical adsorption to fall off, affecting the stability of the emulsion.

[0009] Patent CN108589344A discloses a friction-resistant structural color ink for textiles and its preparation method. This method first quantitatively grafts reactive olefin double bonds onto the molecular chain of a macromolecular trithiocarbonate compound, and then prepares photonic crystal microspheres and a reactive binder respectively by adding an initiator to initiate emulsion polymerization (the dosage of the initiator aqueous solution for the former is 0.5 - 1 wt%, and the polymerization reaction is 2 - 3 h; for the latter is 0.2 - 0.5 wt%, and the reaction is 3 - 4 h). Finally, a cross-linking agent dithiothreitol is added to prepare a structural color ink, and then the ink is inkjet-printed on textiles through an inkjet printer, and a friction-resistant structural color textile is obtained after ultraviolet curing. However, this method requires an additional grafting reaction of olefin double bonds, and the ink preparation process is relatively cumbersome; in addition, a relatively thick ink layer thickness will significantly affect the bottom-layer ultraviolet curing effect, thereby affecting the dry and wet rubbing color fastness and wear resistance, etc.

[0010] Therefore, in the current method system for constructing photonic crystal structural colors using a colloidal nano-microsphere dispersion as digital inkjet printing ink, problems such as the storage and printing stability of the microsphere ink system, the contradiction between low solid content and color saturation, and color fastness still need to be solved urgently. Summary of the Invention

[0011] The present invention aims to provide a method for preparing a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing. Aiming at the problems existing in the existing ink preparation technology, such as insufficient stability of microspheres, difficulty in balancing low solid content and color saturation, and poor fastness of structural color, the present invention proposes a strategy combining surface carboxylated core-shell type nano-microspheres with polymer induction on the fabric surface. Using reversible addition-fragmentation chain transfer polymerization (RAFT) emulsion polymerization method with high monomer conversion rate and good controllability, surface carboxylated core-shell type nano-microspheres are prepared by a one-pot method. On this basis, a colloidal photonic ink system is constructed by compounding specific functional additives, so that it can maintain a stable state for 12 months under conventional storage conditions, and can effectively resist the aggregation of microspheres caused by high shear force and sudden temperature change during the inkjet printing process, avoiding the problem of nozzle clogging. This technical solution significantly improves the color saturation and structural color stability on the premise of ensuring a low solid content of the system. In addition, a water-absorbing polymer layer is used to locally modify the printed area of the fabric as needed, and then the ink is spray-positioned on the area to be printed on the textile by inkjet printing technology. The water-absorbing polymer layer on the base surface can induce the directional close packing of nano-microspheres in a very short time, improving the color saturation without affecting the hand feeling of the fabric. Finally, simple heating and curing promotes the melting, migration and film formation of the soft shell layer between adjacent microspheres, effectively improving the stability and durability of the self-assembled structure.

[0012] To solve the above technical problems, the following technical solutions are adopted:

[0013] The present invention provides a method for preparing a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing, which is characterized in that: a surface carboxylated core-shell structure colloidal microsphere ink is prepared by a one-pot method:

[0014] Add an amphiphilic macromolecular reversible addition-fragmentation chain transfer reagent, a first monomer, deionized water and a water-soluble initiator into a reaction flask and mix them. Pass nitrogen to displace air, gradually raise the temperature to 60-95 °C for reaction, and stir at a speed of 300-1000 r / min for 20-90 min. Then add a pH regulator and a second monomer, and continue the polymerization reaction for 10-50 min. Finally, add a viscosity regulator and a bactericide to the emulsion for compounding, and stir for 30-60 min to obtain a uniformly dispersed photonic crystal ink containing surface carboxylated core-shell type microspheres. The components of the ink are as follows by weight percentage:

[0015] 0.15-9 wt% amphiphilic macromolecular reversible addition-fragmentation chain transfer reagent;

[0016] 0.5-25 wt% first monomer;

[0017] 1.2-25 wt% second monomer;

[0018] 0.05 - 2 wt% initiator;

[0019] 0.01 - 0.05 wt% bactericide;

[0020] 0.05 - 3 wt% pH regulator;

[0021] 0.1 - 1 wt% viscosity regulator.

[0022] After optimization, the structural formula of the diblock copolymer of the surface carboxylated hard core - soft shell microspheres is:

[0023]

[0024] Wherein:

[0025] R1 is from the leaving group of the macromolecular RAFT reagent;

[0026] The general structural formula of the T unit is shown in Formula (Ⅱ);

[0027]

[0028] In Formula (Ⅰ), the repeating unit The common structures are shown in Formula (Ⅲ), (Ⅳ), (Ⅴ) or (Ⅵ); n1 is the average degree of polymerization of the polymer chain segment, n1 = 20 - 100;

[0029]

[0030] The lipophilic unit selects styrene; n2 is the average degree of polymerization of the polystyrene chain segment, n2 = 50 - 200;

[0031] W is from any one of the alkyl dithiocarbonate group, alkyl trithiocarbonate group, benzyl dithiocarbonate group or phenyl dithiocarbonate group of the amphiphilic macromolecular reversible addition - fragmentation chain transfer reagent.

[0032] After optimization, the particle size of the surface carboxylated hard core - soft shell microspheres is 130 - 380 nm, PDI ≤ 0.05, the core thickness is 100 - 360 nm, the shell thickness is 20 - 65 nm, and the core - shell ratio is 1:0.2 - 0.7; the surface carboxyl density of the surface carboxylated hard core - soft shell microspheres is 0.006 - 14.7 mmol / g, and the absolute value of zeta potential > 34 mV.

[0033] After optimization, the amphiphilic macromolecular reversible addition - fragmentation chain transfer reagent is dithiocarbonate or trithiocarbonate, and the structure is shown in Formula (Ⅶ) or (Ⅷ):

[0034]

[0035] Among them, Z is an alkylthio group, phenyl group or benzyl group with 4 to 12 carbon atoms; S is sulfur element; X is a lipophilic monomer, which can be styrene, acrylate or methacrylate; Y is a hydrophilic monomer, which can be acrylic acid or methacrylic acid unit; m and n are the numbers of lipophilic monomers and hydrophilic monomers respectively; m = 3 to 25, n = 12 to 70; the R group is: 1-methylbenzyl, isopropyl acid group, 2-diisobutyric acid group, 3-benzoic acid group; among them, the molecular weight of the amphiphilic macromolecular reversible addition-fragmentation chain transfer reagent is 1000 to 10000.

[0036] After optimization, the ink viscosity is 3 to 25 mPa·s, and the surface tension is 23 to 68 mN / m.

[0037] After optimization, the viscosity regulator is one or a mixture of several of ethylene glycol, ethylene glycol dimethyl ether, diethylene glycol, triethylene glycol, glycerol, n-butanol, 1,2-hexanediol, 1,2-propanediol, 1,5-pentanediol; the bactericide is any one of benzisothiazolinone (BIT), dodecyl dimethyl benzyl ammonium chloride (DDBAC), and isothiazolinone antibacterial agents.

[0038] After optimization, the pH regulator is any one of sodium carbonate, sodium bicarbonate, sodium hydroxide, triethanolamine, and disodium hydrogen phosphate, and the pH value of the ink system is adjusted to 7 to 8.5; the initiator is selected from one or a combination of potassium persulfate, ammonium persulfate, or azobisisobutyronitrile.

[0039] An inkjet printing method for highly stable self-crosslinking colloidal photonic ink, which is characterized by including the following steps:

[0040] (1) Local polymer coating modification of the fabric

[0041] According to the requirements of the expected pattern effect, the printing area on the surface of the textile is treated by digital spraying of a water-absorbing polymer solution as needed. The polymer dosage is 0.1 to 0.7 wt%, and the coating amount is 4 to 10 g / m 2 dry weight, and treated at a temperature of 40 to 90 °C for 3 to 10 min to cure into a film;

[0042] (2) Inkjet printing

[0043] Add the ink prepared in step (1) to the ink cartridge of the inkjet printer, set the printing resolution to 600 to 1200 DPI, the number of passes to 1 to 4 Pass, the driving waveform to control the ink droplet size to 6 to 32 pL, and the spraying frequency to 20 to 30 kHz. Then, according to the designed pattern, accurately position and print in the locally modified area, and the ink quickly induces self-assembly to form structural color.

[0044] (3) Thermal stabilization treatment

[0045] The fabric completed with inkjet printing is placed into a forced-air oven, and heat stabilization treatment is carried out at a constant temperature of 60-85 °C for 10-20 min.

[0046] After optimization, the water-absorbing polymer solution is one of sodium alginate, polyacrylic acid, polyacrylamide, polyvinyl alcohol, polyethylene glycol (PEG) and its derivatives or starch derivatives, and the viscosity is 50-250 mPa·s.

[0047] After optimization, the textile to be printed is selected from cotton fabrics, polyester fabrics, nylon, aramid fabrics, silk fabrics, polyester-cotton blended fabrics or polyester-ammonia blended fabrics; the color of the textile is selected as black.

[0048] Due to the adoption of the above technical solutions, the following beneficial effects are achieved:

[0049] 1. The present invention provides a method for preparing carboxyl surface-functionalized nano microspheres by reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization one-pot method. Through the precise controllability of RAFT polymerization, the uniform distribution of hydrophilic carboxyl groups on the surface of the microspheres in the form of covalent bonds and the precise regulation of their content are realized, so that the nano microspheres can maintain excellent dispersion stability under extreme environments of inkjet printing with multi-field alternation (such as sudden temperature change, shear mutation, etc.). Compared with the traditional use of physical adsorption-type emulsifiers (such as sodium dodecyl sulfate, SDS), the stability problems such as aggregation and nozzle blockage caused by desorption and shedding are avoided.

[0050] 2. The binding force between the colloidal photonic crystal and the substrate is the key to determining the abrasion resistance and color stability of the structural color material. The present invention ingeniously designs a nano microsphere photonic ink with a hard core-soft shell structure by RAFT emulsion polymerization one-pot method. Utilizing the characteristics of heat melting and cold solidification of the shell layer, the soft shell is melted, migrated and solidified into a film through baking treatment after printing, effectively improving the stability of the self-assembled structure and the stability of the structural color.

[0051] 3. The present invention innovatively constructs a water-absorbing polymer-induced layer. Relying on the physical adsorption of water molecules by carboxylic acid groups in the polymer, the water molecules around the microspheres migrate to the water-absorbing polymer layer, effectively and directionally inducing the orderly arrangement of low-solid-content carboxylated nano microspheres on the fabric surface, and self-assembling into a photonic crystal with high saturation and iridescent effect, breaking through the technical bottleneck of traditional low-solid-phase concentration color development technology. Specific embodiments

[0052] The technical solutions of the present invention will be described in detail below in combination with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0053] In the present invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used can be obtained from the market or are commonly used in the art. The methods in the following examples are conventional methods in the art unless otherwise specified.

[0054] The chemical structural formula of the amphiphilic macromolecular reversible addition-fragmentation chain transfer reagent used in the examples of the present invention is:

[0055]

[0056] Example 1

[0057] (1) Add 5 g of amphiphilic macromolecular reversible addition-fragmentation chain transfer reagent (1), 5 g of acrylic acid (AA), 75 g of water, and 0.058 g of ammonium persulfate into a reaction flask and mix. Pass nitrogen to displace air, gradually heat up to 75 °C for reaction, and stir at a speed of 340 r / min for 60 min. Then add 1 g of sodium carbonate and 10 g of styrene (St), and continue the polymerization reaction for 20 min. Finally, add 0.5 g of glycerol and 0.03 g of benzisothiazolinone (BIT) to the emulsion for compounding, and stir for 30 min to obtain a photon crystal ink with uniformly dispersed surface carboxylated core-shell microspheres.

[0058] (2) Use a 0.3 wt% sodium alginate solution to perform on-demand digital spraying treatment on the printed parts of the cotton fabric surface, with a coating amount of 6 g / m 2 dry weight, and treat at a temperature of 40 °C for 9 min to cure into a film.

[0059] (3) Add the photon ink prepared in step (1) to the inkjet printer cartridge, set the printing resolution to 600 DPI, the number of passes to 1 Pass, the driving waveform to regulate the ink droplet size to 26 pL, and the ejection frequency to 21 kHz. Then precisely adjust the nozzle position so that it can be positioned and ejected according to the designed pattern on the textile that has been pre-treated with a water-absorbing polymer layer.

[0060] (4) Put the printed fabric into a forced-air oven, keep the temperature constant at 70 °C for thermal curing for 10 min, so that the colloidal microspheres complete the self-assembly process on the fabric surface, producing a structural color effect.

[0061] Example 2

[0062] (1) Add 2 g of amphiphilic macromolecule reversible addition-fragmentation chain transfer reagent (2), 5 g of butyl acrylate (BA), 82 g of water, and 0.065 g of potassium persulfate into a reaction flask, mix them, displace the air with nitrogen, gradually heat up to 65 °C for reaction, and stir at a speed of 380 r / min for 30 min. Then add 0.5 g of triethanolamine and 8 g of St, and continue the polymerization reaction for 30 min. Finally, add 0.2 g of 1,2-propanediol and 0.02 g of dodecyldimethylbenzylammonium chloride (DDBAC) to the emulsion for compounding, and stir for 35 min to obtain a photon crystal ink with uniformly dispersed surface carboxylated core-shell microspheres.

[0063] (2) Use a 0.2 wt% polyacrylic acid solution to perform on-demand digital spraying treatment on the printed parts of the polyester fabric surface, with a coating amount of 8 g / m 2 dry weight, and treat it at a temperature of 50 °C for 7 min to cure into a film.

[0064] (3) Add the photon ink prepared in step (1) into the inkjet printer cartridge, set the printing resolution to 900 DPI, the number of passes to 2 Pass, adjust the driving waveform to control the ink droplet size to 24 pL, and the ejection frequency to 26 kHz. Then precisely adjust the nozzle position so that it can be positioned and ejected according to the designed pattern on the textile that has been pre-treated with a water-absorbing polymer layer.

[0065] (4) Put the printed fabric into a forced-air oven, keep the temperature constant at 70 °C for thermal curing for 15 min, so that the colloidal microspheres complete the self-assembly process on the fabric surface, producing a structural color effect.

[0066] Example 3

[0067] (1) Add 9 g of amphiphilic macromolecule reversible addition-fragmentation chain transfer reagent (1), 15 g of acrylamide (AM), 68 g of water, and 0.46 g of ammonium persulfate into a reaction flask, mix them, displace the air with nitrogen, gradually heat up to 65 °C for reaction, and stir at a speed of 400 r / min for 30 min. Then add 2 g of disodium hydrogen phosphate and 20 g of St, and continue the polymerization reaction for 40 min. Finally, add 0.5 g of ethylene glycol and 0.05 g of isothiazolinone bactericide to the emulsion for compounding, and stir for 50 min to obtain a photon crystal ink with uniformly dispersed surface carboxylated core-shell microspheres.

[0068] (2) Use a 0.4 wt% sodium alginate solution to perform on-demand digital spraying treatment on the printed parts of the nylon surface, with a coating amount of 5 g / m 2 dry weight, and treat it at a temperature of 60 °C for 4 min to cure into a film.

[0069] (3) Add the photon ink configured in step (1) to the inkjet printer cartridge. Set the printing resolution to 1000 DPI, the number of passes to 3 Passes, the drive waveform to regulate the droplet size to 20 pL, and the ejection frequency to 25 kHz. Then precisely adjust the nozzle position so that it can perform positioning ejection on the textile that has been pre-treated with a water-absorbing polymer layer according to the designed pattern.

[0070] (4) Put the printed fabric into a forced-air oven, keep the temperature constant at 65 °C for thermal curing for 10 min, so that the colloidal microspheres complete the self-assembly process on the fabric surface, producing a structural color effect.

[0071] Example 4

[0072] (1) Add 4 g of amphiphilic macromolecule reversible addition-fragmentation chain transfer reagent (2), 12 g of AA, 67 g of water, and 0.25 g of potassium persulfate into a reaction flask and mix. Pass nitrogen to displace air, gradually raise the temperature to 75 °C for reaction, and stir at a speed of 380 r / min for 30 min. Then add 0.7 g of sodium hydroxide (NaOH) and 15 g of St, and continue the polymerization reaction for 35 min. Finally, add 0.8 g of 1,5-pentanediol and 0.05 g of DDBAC to the emulsion for compounding, and stir for 50 min to obtain a uniformly dispersed photon crystal ink containing surface carboxylated core-shell microspheres.

[0073] (2) Use a 0.5 wt% polyvinyl alcohol solution to perform on-demand digital spraying treatment on the printing area of the polyester fabric surface, with a coating amount of 5 g / m 2 dry weight, and treat it at 80 °C for 4 min to cure into a film.

[0074] (3) Add the photon ink configured in step (1) to the inkjet printer cartridge. Set the printing resolution to 1000 DPI, the number of passes to 4 Passes, the drive waveform to regulate the droplet size to 13 pL, and the ejection frequency to 20 kHz. Then precisely adjust the nozzle position so that it can perform positioning ejection on the textile that has been pre-treated with a water-absorbing polymer layer according to the designed pattern.

[0075] (4) Put the printed fabric into a forced-air oven, keep the temperature constant at 65 °C for thermal curing for 10 min, so that the colloidal microspheres complete the self-assembly process on the fabric surface, producing a structural color effect.

[0076] Example 5

[0077] (1) Add 1.2 g of amphiphilic macromolecule reversible addition-fragmentation chain transfer reagent (1), 6 g of methyl acrylate (MA), 80 g of water, and 0.1 g of ammonium persulfate into a reaction flask and mix them. Pass nitrogen to displace air, gradually heat up to 65 °C for reaction, and stir at a speed of 420 r / min for 30 min. Then add 0.3 g of disodium hydrogen phosphate and 8 g of St, and continue the polymerization reaction for 40 min. Finally, add 0.4 g of glycerol and 0.02 g of BIT to the emulsion for compounding, and stir for 45 min to obtain a photon crystal ink with uniformly dispersed surface carboxylated core-shell microspheres.

[0078] (2) Use a 0.2 wt% polyacrylamide solution to perform on-demand digital spraying treatment on the printed parts of the cotton fabric surface, with a coating amount of 4 g / m 2 dry weight, and treat it at a temperature of 90 °C for 3 min to cure into a film.

[0079] (3) Add the photon ink prepared in step (1) into the ink cartridge of an inkjet printer. Set the printing resolution to 1100 DPI, the number of passes to 3 Pass, the driving waveform to regulate the ink droplet size to 10 pL, and the ejection frequency to 24 kHz. Then precisely adjust the nozzle position so that it can be positioned and ejected according to the designed pattern on the textile that has been pre-treated with a water-absorbing polymer layer.

[0080] (4) Put the printed fabric into a blast drying oven, keep the temperature constant at 80 °C for heat curing for 10 min, so that the colloidal microspheres complete the self-assembly process on the fabric surface, producing a structural color effect.

[0081] Example 6

[0082] (1) Add 0.5 g of amphiphilic macromolecule reversible addition-fragmentation chain transfer reagent (2), 8 g of AM, 70 g of water, and 0.018 g of ammonium persulfate into a reaction flask and mix them. Pass nitrogen to displace air, gradually heat up to 75 °C for reaction, and stir at a speed of 390 r / min for 30 min. Then add 1.5 g of triethanolamine and 18 g of St, and continue the polymerization reaction for 50 min. Finally, add 0.6 g of ethylene glycol dimethyl ether and 0.01 g of isothiazolinone to the emulsion for compounding, and stir for 60 min to obtain a photon crystal ink with uniformly dispersed surface carboxylated core-shell microspheres.

[0083] (2) Use a 0.4 wt% polyacrylic acid solution to perform on-demand digital spraying treatment on the printed parts of the cotton fabric surface, with a coating amount of 7 g / m 2 dry weight, and treat it at a temperature of 65 °C for 6 min to cure into a film.

[0084] (3) Add the photon ink configured in step (1) to the inkjet printer cartridge, set the printing resolution to 1200 DPI, the number of passes to 4 Passes, the driving waveform to regulate the droplet size to 15 pL, and the ejection frequency to 28 kHz. Then precisely adjust the nozzle position so that it can perform positioning ejection according to the designed pattern on the textile that has been pre-treated with the water-absorbing polymer layer.

[0085] (4) Put the printed fabric into a forced-air oven, keep the temperature constant at 60 °C for thermal curing for 20 minutes, so that the colloidal microspheres complete the self-assembly process on the fabric surface, producing a structural color effect.

[0086] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all covered by the protection scope of the present invention.

Claims

1. A preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing, characterized in that: Preparation of surface carboxylated core-shell structured colloidal microsphere ink by one-pot method: Add amphiphilic macromolecular reversible addition-fragmentation chain transfer agent, the first monomer, deionized water and water-soluble initiator into a reaction flask and mix them. Pass nitrogen to displace air, gradually heat up to 60 - 95 °C for reaction, and stir at a speed of 300 - 1000 r / min for 20 - 90 min; then add pH regulator and the second monomer, and continue the polymerization reaction for 10 - 50 min; finally, add viscosity regulator and bactericide to the emulsion for compounding, and stir for 30 - 60 min to obtain a photon crystal ink with uniformly dispersed surface carboxylated core-shell type microspheres; the components of the ink are as follows by weight percentage: 0.15 - 9 wt% amphiphilic macromolecular reversible addition-fragmentation chain transfer agent; 0.5 - 25 wt% the first monomer; 1.2 - 25 wt% the second monomer; 0.05 - 2 wt% initiator; 0.01 - 0.05 wt% bactericide; 0.05 - 3 wt% pH regulator; 0.1 - 1 wt% viscosity regulator.

2. The preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing according to claim 1, characterized in that: The structural formula of the diblock copolymer of the surface carboxylated core-shell type microspheres is: Wherein: R1 comes from the leaving group of the amphiphilic macromolecular reversible addition-fragmentation chain transfer agent; The structural general formula of the T unit is shown in formula (Ⅱ); In formula (I), the chain link has common structures as shown in formulas (III), (IV), (V) or (VI); n1 is the average degree of polymerization of the polymer chain segment, and n1 = 20 to 100; The lipophilic unit selects styrene; n2 is the average degree of polymerization of the polystyrene chain segment, n2 = 50 - 200; W comes from any one of the alkyl dithiocarbonate group, alkyl trithiocarbonate group, benzyl dithiocarbonate group or phenyl dithiocarbonate group of the amphiphilic macromolecular reversible addition-fragmentation chain transfer agent.

3. The preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing according to claim 1, characterized in that: The particle size of the surface carboxylated core-shell type microspheres is 130 - 380 nm, PDI ≤ 0.05, the core thickness is 100 - 360 nm, the shell thickness is 20 - 65 nm, and the core-shell ratio is 1:0.2 - 0.7; the surface carboxyl density of the surface carboxylated core-shell type microspheres is 0.006 - 14.7 mmol / g, and the absolute value of zeta potential > 34 mV.

4. The preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing according to claim 1, characterized in that: The amphiphilic macromolecular reversible addition-fragmentation chain transfer agent is dithiocarbonate or trithiocarbonate, and the structure is shown in formula (Ⅶ) or (Ⅷ): Wherein, Z is an alkylthio group with 4 to 12 carbon atoms, phenyl group, benzyl group; S is sulfur element; X is a lipophilic monomer, and styrene, acrylate or methacrylate can be selected; Y is a hydrophilic monomer, and acrylic acid or methacrylic acid unit can be selected; m and n are the numbers of lipophilic monomers and hydrophilic monomers respectively; m = 3 - 25, n = 12 - 70; the R group is: 1-methylbenzyl, isopropyl acid group, 2-diisobutyric acid group, 3-benzoic acid group; among them, the molecular weight of the amphiphilic macromolecular reversible addition-fragmentation chain transfer agent is 1000 - 10000.

5. The preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing according to claim 1, characterized in that: The viscosity of the ink is 3 - 25 mPa·s, and the surface tension is 23 - 68 mN / m.

6. The preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing according to claim 1, characterized in that: The viscosity regulator is one or a mixture of several of ethylene glycol, ethylene glycol ether, diethylene glycol, triethylene glycol, glycerol, n-butanol, 1,2-hexanediol, 1,2-propanediol, 1,5-pentanediol; the bactericide is any one of benzisothiazolinone (BIT), dodecyldimethylbenzylammonium chloride (DDBAC), and isothiazolinone bactericides.

7. The preparation method of a highly stable self-crosslinking colloidal photonic ink for textile inkjet printing according to claim 1, characterized in that: The pH regulator is any one of sodium carbonate, sodium bicarbonate, sodium hydroxide, triethanolamine, and disodium hydrogen phosphate, and the pH value of the ink system is adjusted to 7-8.5; the initiator is selected from one or a combination of potassium persulfate, ammonium persulfate, or azobisisobutyronitrile.

8. The inkjet printing method of the highly stable self-crosslinking colloidal photonic ink according to claim 1, characterized in that It includes the following steps: (1) Local polymer coating modification of the fabric According to the requirements of the expected pattern effect, the printed parts on the surface of the textile are treated by digital spraying of a water-absorbing polymer solution as needed, with the polymer dosage being 0.1 - 0.7 wt%, and the coating amount being 4 - 10 g / m 2 dry weight, and treated at a temperature of 40 - 90 °C for 3 - 10 min to form a cured film; (2) Inkjet printing Add the prepared photonic ink to the inkjet printer cartridge, set the printing resolution to 600-1200 DPI, the number of passes to 1-4 passes, the driving waveform to control the ink droplet size to 6-32 pL, and the ejection frequency to 20-30 kHz. Then, accurately position and print according to the designed pattern in the locally modified area, and the ink quickly induces self-assembly to form structural color; (3) Thermal stabilization treatment Put the fabric that has completed inkjet printing into a forced-air oven, keep the temperature constant at 60-85 °C for thermal stabilization treatment, and the time is 10-20 min.

9. The inkjet printing method of the highly stable self-crosslinking colloidal photonic ink according to claim 8, characterized in that: In the step (1), the water-absorbing polymer solution is one of sodium alginate, polyacrylic acid, polyacrylamide, polyvinyl alcohol, polyethylene glycol (PEG) and its derivatives, or starch derivatives, and the viscosity is 50-250 mPa·s.

10. The inkjet printing method of the highly stable self-crosslinking colloidal photonic ink according to claim 8, characterized in that: In the step (1), the textile fabric to be printed is selected from cotton fabric, polyester fabric, nylon, aramid fabric, silk fabric, polyester-cotton blended fabric or polyester-ammonia blended fabric; the color of the textile fabric is selected as black.

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