Washing-free digital dyeing adhesive with disperse dye one-way loading function and preparation method of washing-free digital dyeing adhesive

Abstract

The invention provides a washing-free digital dyeing adhesive with a disperse dye one-way loading function and a preparation method of the washing-free digital dyeing adhesive. The washing-free digital dyeing adhesive is prepared by taking dibutyltin dilaurate as a catalyst, isophorone diisocyanate, polyadipic acid-1, 4-butanediol ester, hydroxyl-terminated polyoxy silane, 2, 2-dimethylolbutanoic acid, 1, 4-butanediol ester, 1, 4-butanediol ester, hydroxyl-terminated polyoxy silane, 2, 2-dimethylolbutanoic acid, 1, 4-butanediol ester, 1, 4-butanediol sequentially carrying out polycondensation and chain extension reaction on 1, 4-butanediol, and then adding 2-diacetylmonoxime for terminating; and finally, neutralizing to obtain the organic silicon modified waterborne polyurethane emulsion. The adhesive is applied to digital jet dyeing of disperse dyes of polyester fabrics, the procedures of reduction cleaning and water washing can be omitted, the color yield of the dyed fabrics is improved by 14-20% compared with that of pure dye ink jet dyeing, the dry rubbing fastness is improved by 2 levels, the wet rubbing fastness is improved to 1 level, and the adhesive has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of printing and dyeing auxiliaries, and particularly relates to a water-free digital dyeing adhesive with a disperse dye unidirectional delivery function and a preparation method thereof. Background Art

[0002] Polyester fabrics are often dyed with disperse dyes, and the conventional dyeing methods are mainly dip dyeing and pad dyeing. After dyeing, it must undergo reduction cleaning and multiple washing processes to remove surface floating colors, which will produce a large amount of dyeing wastewater and impose a serious burden on the environment. Digitalization and greening are the themes of the future development of the textile printing and dyeing industry. Disperse dye water-free digital jet dyeing combines digital jet technology with disperse dye water-free printing and dyeing technology. It has the advantages of simple process, emission reduction and carbon reduction, dye and chemical saving, and personalized fast response. It is a revolutionary breakthrough in polyester fabric clean dyeing technology. This technology will promote the digital transformation and upgrading and sustainable development of the printing and dyeing industry.

[0003] Disperse dyes have similar solubility parameters to polyester fibers and have an affinity for fibers. Their dyeing can be regarded as the formation of a "solid solution". When the dyeing temperature is higher than the glass transition temperature of polyester, the dyes on the fiber surface diffuse and dissolve in the pores of the amorphous region of the polyester fiber in molecular form, and are adsorbed and fixed to the fibers through hydrogen bonds, van der Waals forces, hydrophobic bonds, and other interactions. Based on this, by utilizing the thermal sublimation of disperse dyes and the film-forming properties of polymer adhesives, and based on the difference in solubility parameters between disperse dyes and polymer films, a large amount of dyes will migrate, diffuse, and dye and fix to the polyester fabric during high-temperature baking; a small amount of dyes will dissolve and fix in the polymer film. With the collaboration of the two, the subsequent reduction cleaning and washing steps can be omitted, achieving a water-free effect. At present, there are relevant reports on water-free printing and dyeing of polyester fabrics in China. The patent document with publication number CN107988822A discloses "High dye-carrying adhesive for water-free printing of disperse dyes and preparation method thereof", which provides a preparation method of a silicone-modified acrylate adhesive with high dye-carrying capacity, which can improve the color yield and friction color fastness of printed fabrics. The patent document with publication number CN107988822A discloses "A fluorosilicone-modified polyacrylate adhesive and preparation method thereof", which provides a preparation method of a fluorosilicone-modified polyacrylate adhesive for hot-melt dyeing of polyester liquid disperse dyes, which can prevent migration and obtain good color yield and color fastness.

[0004] However, conventional water-free adhesive films will dissolve and retain a portion of disperse dyes. During the use process, the dyes that have not been dyed on the fibers will be affected by the external environment (light, heat, friction, etc.) and migrate and diffuse to the surface of the film, resulting in poor color fastness of the printed and dyed fabrics. Therefore, increasing the difference in solubility parameters between disperse dyes and polymers, so that the dyes migrate and diffuse unidirectionally toward the fabric as much as possible, and migrate to the film surface as little as possible or remain in the film, is the key to achieving good polyester water-free printing and dyeing effects.

[0005] At present, most of the existing polyester water-free adhesives are modified acrylics, which have problems such as unsatisfactory friction resistance and color fastness. Compared with polyacrylates, water-based polyurethane connects soft and hard segments through hydrogen bonds. Compared with polyacrylates, there are more hydrogen bonds in the water-based polyurethane segments, so it has better bonding performance. The molecular structure of polyester water-free adhesives is designed based on the difference in solubility parameters between adhesives and disperse dyes. Monomers need to be optimized based on the solubility parameter principle in order for the synthesized water-based polyurethane to obtain a high unidirectional dye delivery effect. Therefore, in order to improve the surface color yield of polyester water-free spray-dyed fabrics and at the same time have good color fastness, it is urgently needed to develop modified water-based polyurethane adhesives with excellent performance. Summary of the invention

[0006] The current problem with the water-free spray-dyeing technology of disperse dyes is that some dyes remain in the adhesive film, resulting in poor color yield and color fastness of the spray-dyed fabric. In order to achieve water-free digital spray-dyeing of polyester, according to the migration mode of dyes in the film, when selecting water-based polyurethane synthetic monomers, monomers with large differences in solubility parameters with disperse dyes are selected to expand the solubility parameter difference between disperse dyes and adhesives, so as to achieve the effect of unidirectional delivery of disperse dyes and promote more disperse dyes to be dyed on the fabric. At the same time, by utilizing the good bonding properties of water-based polyurethane, the film on the surface of the fabric can withstand strong external mechanical effects, thereby improving the friction color fastness of polyester water-free fabrics.

[0007] Firstly, according to the solubility parameters, rigid polyester diol poly(1,4-butylene adipate) with strong cohesive energy and excellent bonding performance is selected as the soft segment, 1,4-butylene glycol is used as the chain extender, and 2,2-dihydroxymethylbutyric acid is used as the hydrophilic monomer.

[0008] Secondly, the wet friction color fastness of water-free spray-dyed fabrics mainly depends on the low friction coefficient, water resistance, mechanical properties and bonding properties of the fabric after the polymer emulsion forms a film. In order to improve the low friction coefficient and softness of the coating, polydimethylsiloxane, which has a large difference in solubility parameters from disperse dyes, is introduced into waterborne polyurethane as a soft segment at the same time, further expanding the difference in solubility parameters to obtain water-free spray-dyed fabrics with high color yield. At the same time, the high-temperature phase separation characteristics of the silicone segment and good hydrophobicity and smoothness are used to improve the color fastness of the spray-dyed fabric.

[0009] Finally, in order to further obtain better bonding performance, 2-butanone oxime is used as a blocking agent. The blocking agent will be unblocked during high-temperature baking, releasing active isocyanate groups, which can cross-link with polyester fabrics to improve the bonding strength of the film and, to a certain extent, improve the color fastness of the spray-dyed fabric.

[0010] Based on the above analysis, the present invention provides a water-free digital dyeing adhesive with disperse dye unidirectional delivery function and a preparation method thereof. The silicone-modified waterborne polyurethane is applied to digital spray dyeing of polyester fabrics, which can avoid reduction cleaning and water washing processes, and the dyed fabric has a higher surface color yield and dry / wet friction color fastness, and has broad application prospects.

[0011] A water-free digital dyeing adhesive with a disperse dye unidirectional delivery function, the structure of the water-free digital dyeing adhesive is as follows:

[0012]

[0013] Among them, R1 comes from poly(1,4-butylene adipate) (PBA), R2 comes from hydroxyl-terminated polysiloxane (PDMS), R3 comes from 2,2-dihydroxymethylbutyric acid, and R4 comes from 1,4-butanediol (BDO).

[0014] A water-free digital dyeing adhesive with a disperse dye unidirectional delivery function is obtained by polymerizing R1 from poly(1,4-butylene adipate) (PBA), R2 from hydroxyl-terminated polysiloxane (PDMS), R3 from 2,2-dihydroxymethylbutyric acid, and R4 from 1,4-butanediol (BDO) as polymerization monomers.

[0015] A water-free digital dyeing adhesive with disperse dye unidirectional delivery function is prepared by any of the following methods.

[0016] The present invention also provides a method for preparing the above-mentioned water-free digital dyeing adhesive with the function of one-way delivery of disperse dyes, comprising: polycondensation reaction of polyadipate-1,4-butylene glycol ester, hydroxyl-terminated polyoxysilane and a corresponding amount of isophorone diisocyanate under the action of a catalyst to obtain an organosilicon-modified waterborne polyurethane prepolymer P1; adding 2,2-dihydroxymethylbutyric acid, continuing the polycondensation reaction with P1 and a corresponding amount of isophorone diisocyanate, to obtain an organosilicon-modified waterborne polyurethane prepolymer P2; then adding 1,4-butanediol, carrying out a chain extension reaction with P2 and a corresponding amount of isophorone diisocyanate; finally, end-capping with 2-butanone oxime; and post-processing to obtain the water-free digital dyeing adhesive with the function of one-way delivery of disperse dyes.

[0017] In the present invention, all reactive monomers include isophorone diisocyanate (IPDI), poly(1,4-butylene adipate) (PBA), hydroxyl-terminated polysiloxane (PDMS), 2,2-dihydroxymethylbutyric acid (DBA), and 1,4-butanediol (BDO).

[0018] Furthermore, in the reaction monomer, the molar ratio of isocyanate group to total active hydroxyl group, i.e., the chain extension coefficient R value is (1.0-1.7): 1. Among them, the monomer containing isocyanate group is IPDI, and the monomer containing hydroxyl group includes PBA, PDMS, DBA, and BDO.

[0019] Furthermore, the synthetic monomers are composed of hard monomers and soft segments, and the hard monomer ratio is limited, that is, the hard segment content (H) accounts for 34-46% of the monomer mass. Among them, the hard monomers include IPDI, DBA, BDO, and the soft segments are PBA and PDMS.

[0020] Furthermore, the mass of the isophorone diisocyanate accounts for 25-36% of the total mass of the monomers, the mass of the poly(1,4-butylene adipate) accounts for 48-62% of the total mass of the monomers, the mass of the hydroxyl-terminated polysiloxane accounts for 2-11% of the total mass of the monomers; the mass of the 2,2-dihydroxymethylbutyric acid accounts for 4-6% of the total mass of the monomers; the mass of the 1,4-butylene glycol accounts for 1.5-6% of the total mass of the monomers; and the mass of the catalyst accounts for 0.02-0.04% of the total mass of the monomers.

[0021] The present invention also provides a method for preparing the above-mentioned water-free digital dyeing adhesive having a disperse dye unidirectional delivery function, comprising the following steps:

[0022] (1) First, dry PBA, PDMS, and DBA in a vacuum oven.

[0023] (2) Using dibutyltin dilaurate as a catalyst, IPDI, PBA, and PDMS were added into a four-necked flask in sequence, and the temperature was raised under nitrogen protection to carry out a condensation reaction to obtain a silicone-modified waterborne polyurethane prepolymer P1.

[0024] (3) Pour DBA into N-methylpyrrolidone to dissolve, then add it into a four-necked flask and continue the reaction to obtain silicone-modified waterborne polyurethane prepolymer P2. During the reaction, observe the change in the viscosity of the system, and add an appropriate amount of acetone to reduce the viscosity.

[0025] (4) Initial cooling and adding BDO for chain extension reaction.

[0026] (5) Cooling again, adding 2-butanone oxime for end-capping, taking samples at intervals, and monitoring by infrared spectroscopy until the characteristic peak of the NCO group disappears completely.

[0027] (6) Finally, the temperature is lowered, triethylamine is added for neutralization, and then deionized water is added for high-speed emulsification, and rotary evaporation is performed to obtain a silicone-modified waterborne polyurethane emulsion.

[0028] Preferably, in step (1), the temperature of the vacuum oven is 70-90° C., and the drying time is 1-3 h.

[0029] Preferably, in step (2), the molar ratio of isocyanate groups to total active hydroxyl groups is (1.0-1.7):1, more preferably 1.33-1.36:1; more specifically preferably 1.34-1.35:1; more specifically preferably 1.34:1 or 1.35:1.

[0030] Preferably, in step (2):

[0031] The mass of IPDI accounts for 29-36% of the total raw material mass; more preferably 30-36%; more preferably 32-34%; more preferably 32-33%. More preferably, the mass of IPDI accounts for 32%, 32.5%, 33% of the total monomer mass.

[0032] The mass of PBA accounts for 48-58% of the total mass of monomers; more preferably 48-55%; more preferably 50-55%; and more preferably 51-53%. As a specific preference, the mass of PBA accounts for 52-53% of the total mass of raw materials; more preferably 52%, 52.5%, 53%.

[0033] The mass of PDMS accounts for 2-10% of the total mass of the monomers, more preferably 4-8%, and more specifically 5-7%. Furthermore, the mass of PDMS accounts for 6% or 6.1% of the total mass of the monomers.

[0034] Preferably, in step (2), the mass of dibutyltin dilaurate accounts for 0.02-0.04% of the total mass of the monomers, and more preferably 0.03%.

[0035] Preferably, in step (2), the heating temperature is 75-85° C. and the reaction time is 1-3 h.

[0036] Preferably, in step (3), DBA accounts for 4-6% of the total weight of the monomers, and the weight of N-methylpyrrolidone accounts for 200-220% of the weight of DBA. Preferably, DBA accounts for 5% of the total weight of the monomers, and the weight of N-methylpyrrolidone accounts for 210% of the weight of DBA.

[0037] Preferably, in step (3), the reaction temperature is 75-85° C. and the reaction time is 1-3 h.

[0038] Preferably, in step (4), the reaction system is cooled to 65-75° C., and the chain extension reaction time is 1-2 h.

[0039] Preferably, in step (4), BDO accounts for 2-6% of the total weight of the monomers, more preferably 3-4%, even more preferably 3.5-4%, and specifically preferably 3.8%, 3.9%, or 4%.

[0040] Preferably, in step (5), the amount of 2-butanone oxime added is calculated by the number of moles of the remaining unreacted isocyanate groups according to the molar ratio of isocyanate groups to total active hydroxyl groups (1.0 to 1.7):1. More preferably, when the molar ratio of isocyanate groups to total active hydroxyl groups is 1.35:1, the amount of 2-butanone oxime added accounts for 8% of the total mass of the monomers.

[0041] Preferably, in step (5), the end-capping reaction temperature is 55 to 65° C., and the end-capping time is 2 to 4 hours.

[0042] Preferably, in step (6), the triethylamine accounts for 4-6% of the total mass of the monomers, and the amount of deionized water added accounts for 186-300% of the total mass of the monomers. More preferably, the triethylamine accounts for 5% of the total mass of the monomers, and the amount of deionized water added accounts for 243% of the total mass of the monomers.

[0043] Preferably, in step (6), the rotation speed during emulsification is 750-850 rpm, and the emulsification time is 0.5-1.5 h.

[0044] Preferably, in step (6), the rotary evaporation temperature is 35-45° C., and the rotary evaporation time is 0.5-1.5 h.

[0045] Preferably, the molecular weight of PBA is 1500 to 3000, and the molecular weight of PDMS is 500 to 1500. Specifically preferably, the molecular weight of PBA is 2000, and the molecular weight of PDMS is 1000.

[0046] Further, the calculations of R value, PDMS content, and hard segment content (H) are as follows:

[0047]

[0048]

[0049]

[0050] The preparation method of the present invention selects waterborne polyurethane synthetic monomers, and uses polysiloxane segments to modify waterborne polyurethane to prepare an organosilicon-modified waterborne polyurethane adhesive with disperse dye unidirectional delivery function. The adhesive prepared by the present invention is used in the water-free digital spray-dyeing of disperse dyes on polyester fabrics, which not only can avoid the reduction cleaning and washing steps, but also has high surface color yield and color fastness of the spray-dyed fabric, and has broad application prospects.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention uses the difference in solubility parameters between waterborne polyurethane synthetic monomers and disperse dyes to synthesize waterborne polyurethane from the preferred monomers, thereby expanding the difference in solubility parameters. Meanwhile, waterborne polyurethane is modified by polysiloxane to further expand the difference in solubility parameters. On the one hand, the difference in solubility parameters can promote disperse dyes to migrate to the surface of fabrics, diffuse and fix to the inside of fibers, thereby increasing the color yield of water-free spray-dyed polyester fabrics; on the other hand, the good bonding performance of waterborne polyurethane itself and the high-temperature phase separation characteristics, hydrophobicity and smoothness of silicone improve the rubbing color fastness of water-free spray-dyed polyester fabrics. Compared with polyester fabrics spray-dyed with pure disperse dye ink, the color yield of the polyester fabrics spray-dyed with silicone-modified waterborne polyurethane is increased by 14-20%, the dry rubbing color fastness is increased by 2 levels, and the wet rubbing color fastness is increased by 1 level.

[0053] Waterborne polyurethane connects soft and hard segments through hydrogen bonds, and there are many hydrogen bonds in the segments, so it has better bonding performance. In the screening of soft segments, the present invention selects rigid polyester diols with large solubility parameter differences from disperse dyes and better adhesion performance as soft segments to obtain better color fastness, and at the same time, by regulating the ratio of soft and hard segments and the chain extension coefficient, the number of hydrogen bonds formed is controlled to ensure that the waterborne polyurethane has good bonding fastness with polyester fabric. Compared with polyester fabrics sprayed with pure dye ink, when the color yield of the spray-dyed fabric is increased, the dry friction color fastness can be increased from level 3-4 to level 4-5.

[0054] The polyoxysilane segment is added to the main chain of waterborne polyurethane as a soft segment. During high-temperature baking, the low surface energy silicone segment will migrate to the surface of the film and form a silicon layer on the surface, which improves the smoothness of the film while reducing the hydrophilicity. It can also prevent the migration and diffusion of dyes outside the film, which is conducive to improving the color fastness of polyester water-free spray-dyed fabrics. Compared with pure dye ink spray-dyed fabrics, the wet friction color fastness of water-free adhesive spray-dyed fabrics is improved from level 3 to level 3-4. Polysiloxane has a smaller solubility parameter, which can further expand the solubility parameter difference and promote more dyes to migrate to the fabric. At the same time, silicone has a lower refractive index, and has an optical deepening effect after film formation, which can further increase the surface color yield.

[0055] In summary, the silicone-modified waterborne polyurethane prepared by the present invention is used in the water-free digital spray-dyeing of polyester, which not only can avoid the reduction cleaning and water washing steps, but also the surface color yield and rubbing color fastness of the spray-dyed fabric are high, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 Infrared spectra of the silicone-modified waterborne polyurethane films prepared in Example 1 with silicone dosages of 0.4 g, 1.2 g, and 2 g, and the waterborne polyurethane film without silicone.

[0057] Figure 2 Schematic diagram of the steps for preparing a water-free digital dyeing adhesive with a unidirectional delivery function of disperse dyes in an embodiment. DETAILED DESCRIPTION

[0058] Below in conjunction with specific embodiment, further elaborate technical scheme of the present invention.It should be understood that these embodiments are only used to illustrate technical scheme of the present invention and are not used to limit the scope of the present invention.After reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0059] In the embodiments, the abbreviations of the raw materials used correspond to the following:

[0060]

[0061] Example 1-1 to Example 1-3: Changing the amount of hydroxyl-terminated polysiloxane

[0062] In Example 1-1 to Example 1-3: the R value is between 1.34 and 1.35; the hard segment content is between 41 and 42 wt%;

[0063] Example 1-1:

[0064] (1) The total amount of monomer input is 19.87g, and the amount of PBA and PDMS input is 11.6g. First, PBA (11.2g) with a molecular weight of 2000, PDMS (0.4g) with a molecular weight of 1000, and 1g of DBA are dried in a vacuum oven at 90℃ for 2h. (2) Using 0.006g of dibutyltin dilaurate as a catalyst, 6.47g of IPDI, a total of 11.6g of PBA and PDMS are added to a four-necked flask in sequence, protected by nitrogen, heated to 80℃, and subjected to condensation reaction for 2h to obtain silicone-modified waterborne polyurethane prepolymer P1.

[0065] (3) Pour 1 g of DBA into 2.1 g of N-methylpyrrolidone to dissolve, then add the solution into the four-necked flask in step (2), and continue the reaction at 80° C. for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P2. During the reaction, observe the change in the viscosity of the system, and add an appropriate amount of acetone to reduce the viscosity.

[0066] (4) The temperature was initially lowered to 70°C, and BDO (0.80 g) was added and the chain extension reaction was continued for 1.5 h.

[0067] (5) The temperature was lowered to 60°C again, and 1.57 g of 2-butanone oxime was added to carry out the end-capping reaction for 2 h. Samples were taken at intervals and monitored by infrared spectroscopy until the characteristic peak of the NCO group completely disappeared.

[0068] (6) Finally, the temperature was lowered to 40° C., 0.68 g of triethylamine was added for neutralization, and then 49 g of deionized water was added. The mixture was emulsified at a speed of 800 rpm for 1 h, and rotary evaporated at 40° C. to obtain a silicone-modified waterborne polyurethane emulsion.

[0069] The preparation methods of Examples 1-2 to 1-3 are the same as those of Example 1-1, and the amounts of materials added are shown in the following table:

[0070]

[0071]

[0072] Three kinds of silicone-modified waterborne polyurethane adhesive products were obtained respectively from Example 1-1 to Example 1-3.

[0073] The polyester fabric is digitally spray-dyed using dye ink prepared by using the organosilicon-modified water-based polyurethane adhesive and liquid disperse dye.

[0074] Dye solution formula: 3wt% liquid disperse red CI167, 8wt% adhesive emulsion, 89wt% deionized water, totaling 100wt%.

[0075] Dyeing process: polyester fabric → spray dyeing → drying (80℃, 2min) → high temperature baking (190℃, 3min) → finished product.

[0076] Under the above conditions, silicone-modified waterborne polyurethane adhesives prepared with different amounts of hydroxyl-terminated polysiloxane were used for water-free digital spray dyeing of polyester fabrics to explore the effect of the amount of hydroxyl-terminated polysiloxane on the color yield (K / S), permeability and color fastness to rubbing of the dyed fabric surface. The results are shown in Table 1.

[0077] Table 1 Effect of the dosage of hydroxyl-terminated polyoxysilane on the water-free digital dyeing performance of polyester fabric

[0078]

[0079] As can be seen from Table 1, with the increase in the amount of hydroxyl-terminated polysiloxane, the color yield of polyester digital spray-dyed fabric gradually increases and then tends to be flat, the color fastness to dry rubbing remains unchanged, and the color fastness to wet rubbing first increases and then decreases. When the amount of hydroxyl-terminated polysiloxane is 1.2g, the color yield of the front and back of the fabric reaches 16.25 and 13.3 respectively, the color fastness to dry rubbing reaches level 4-5, and the color fastness to wet rubbing reaches level 3-4; continuing to increase the amount of silicone segments, the color yield does not change significantly, but the color fastness to wet rubbing decreases.

[0080] The silicone-modified waterborne polyurethane films with silicone dosages of 0.4g, 1.2g, and 2g and the waterborne polyurethane films without silicone were prepared by forming films from the emulsion at room temperature, drying at 80°C for 2min, and baking at 190°C for 3min. The infrared spectra corresponding to the different films are shown in Figure 2. Figure 1 As shown in the figure, WPU is a film formed by waterborne polyurethane without the introduction of silicone modification. Si-0.4 , WPU Si-1.2 , WPU Si-2 The films were formed by silicone-modified waterborne polyurethane with PDMS dosage of 0.4g, 1.2g, and 2g respectively. Figure 1 Medium, 3352cm -1 It is the stretching vibration peak of NH, 2956~2873cm -1 It is the characteristic peak of -CH3 and -CH2, at 2280~2200cm -1 There is no characteristic peak at 1726 cm -1 The characteristic absorption peak at 1524 cm is the overlap of carbamate and acrylate carbonyl groups. -1 The bending vibration peak of NH is 1168cm -1 The absorption peak of OCO is at 1257cm -1 、1022cm -1and 801cm -1 They are the deformation vibration of -CH3 in polysiloxane Si-CH3, the absorption characteristic peaks of Si-O-Si bond and Si-C bond. It can be seen that with the increase of the content of organic silicon chain segment, the intensity of polysiloxane related peaks increases accordingly.

[0081] Example 2: Changing the chain extension coefficient (molar ratio of isocyanate groups to total active hydroxyl groups)

[0082] In Examples 2-1 to 2-3, the fixed hard segment content is between 41 and 42 wt %; the PDMS content is 6 wt %; and R is 1.05, 1.34, and 1.64, respectively;

[0083] (1) The total amount of monomer input is 19.80 g, and then the amount of soft segment is determined. First, 10.4 g of PBA, 1.2 g of PDMS, and 1 g of DBA are dried in a vacuum oven at 90°C for 2 h.

[0084] (2) Using 0.006 g of dibutyltin dilaurate as a catalyst, IPDI (6.05 g), a total of 11.6 g of PBA and PDMS were added into a four-necked flask in sequence, and the temperature was raised to 80° C. under nitrogen protection to carry out a condensation reaction for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P1.

[0085] (3) Pour 1 g of DBA into 2.1 g of N-methylpyrrolidone solution to dissolve, then add the solution into a four-necked flask and continue the reaction for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P2. During the reaction, observe the change in the viscosity of the system, and add an appropriate amount of acetone to reduce the viscosity.

[0086] (4) The temperature was initially lowered to 70°C, and BDO (1.15 g) was added and the chain extension reaction was continued for 1.5 h.

[0087] (5) The temperature was lowered to 60°C again, and 2-butanone oxime (0.27 g) was added to carry out the end-capping reaction for 2 h. Samples were taken at intervals and monitored by infrared spectroscopy until the characteristic peak of the NCO group completely disappeared.

[0088] (6) Finally, the temperature was lowered to 40° C., 0.68 g of triethylamine was added for neutralization, and then 49 g of deionized water was added. The mixture was emulsified at a speed of 800 rpm for 1 h, and rotary evaporated at 40° C. to obtain a silicone-modified waterborne polyurethane emulsion.

[0089] The preparation methods of Examples 2-2 to 2-3 are the same as those of Example 2-1, and the amounts of materials added are shown in the following table:

[0090] Other embodiments Total monomer input IPDI BDO 2-Butanone oxime Example 2-2 19.84g 6.47g 0.77g 1.57g Example 2-3 19.81g 6.73g 0.48g 2.47g

[0091] Three silicone-modified waterborne polyurethane adhesive products were obtained from Example 2-1 to Example 2-3 respectively.

[0092] The polyester fabric is digitally spray-dyed using dye ink prepared by using the organosilicon-modified water-based polyurethane adhesive and liquid disperse dye.

[0093] Dye solution formula: 3wt% liquid disperse red CI167, 8wt% adhesive emulsion, 89wt% deionized water, totaling 100wt%.

[0094] Dyeing process: polyester fabric → spray dyeing → drying (80℃, 2min) → high temperature baking (190℃, 3min) → finished product.

[0095] Under the above conditions, silicone-modified waterborne polyurethane adhesives prepared with different amounts of hydroxyl-terminated polysiloxane were used for water-free digital spray dyeing of polyester fabrics to investigate the effect of the amount of silicone chain segments on the color yield (K / S), permeability and color fastness to rubbing of the dyed fabric surface. The results are shown in Table 2.

[0096] Table 2 Effect of chain extension coefficient on the water-free digital dyeing performance of polyester fabric

[0097]

[0098] As can be seen from Table 2, with the increase of chain extension coefficient R, the color yield of the front side of the spray-dyed fabric increases slightly, while the color yield of the back side decreases slightly, reflecting a slight decrease in dye penetration; the color fastness to dry rubbing and the color fastness to wet rubbing first increase and then remain unchanged. When the chain extension coefficient is 1.34, the color yield of the spray-dyed fabric is good and there is no particularly large difference in the color yield of the front and back sides. The K / S values ​​are 16.25 and 13.3 respectively, and the color fastness to dry and wet rubbing reaches level 4-5 and level 3-4 respectively.

[0099] Example 3-1 to Example 3-4: Changing the ratio of hard segments

[0100] In Examples 3-1 to 3-4, the R value is about 1.35 (Example 3-3 is 1.34, and the rest are 1.35); the PDMS content is 6%; the mass proportions of the hardened segments are 0.33, 0.37, 0.42, and 0.46, respectively;

[0101] (1) The total amount of monomer input is 19.80 g. First, PBA (12 g), 1.2 g of PDMS, and 1 g of DBA were dried in a vacuum oven at 90°C for 2 h.

[0102] (2) Using 0.006 g of dibutyltin dilaurate as a catalyst, IPDI (5.27 g), PBA (13.2 g), 12.4 g, 11.6 g, and 10.8 g, respectively, and PDMS were added into a four-necked flask in sequence. Under nitrogen protection, the temperature was raised to 80° C. and a condensation reaction was carried out for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P1.

[0103] (3) Pour 1 g of DBA into 2.1 g of N-methylpyrrolidone solution to dissolve, then add the solution into a four-necked flask and continue the reaction for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P2. During the reaction, observe the change in the viscosity of the system, and add an appropriate amount of acetone to reduce the viscosity.

[0104] (4) The temperature was initially lowered to 70°C, and BDO (0.33 g) was added and the chain extension reaction was continued for 1.5 h.

[0105] (5) The temperature was lowered to 60°C again, and 2-butanone oxime (1.28 g) was added to carry out the end-capping reaction for 2 h. Samples were taken at intervals and monitored by infrared spectroscopy until the characteristic peak of the NCO group completely disappeared.

[0106] (6) Finally, the temperature was lowered to 40° C., 0.68 g of triethylamine was added for neutralization, and then 49 g of deionized water was added. The mixture was emulsified at a speed of 800 rpm for 1 h, and then rotary evaporated at 40° C. to obtain a silicone-modified waterborne polyurethane emulsion.

[0107] The polyester fabric is digitally spray-dyed using dye ink prepared by using the organosilicon-modified water-based polyurethane adhesive and liquid disperse dye.

[0108] The preparation methods of Examples 3-2 to 3-4 are the same as those of Example 3-1, and the amounts of materials added are shown in the following table:

[0109]

[0110]

[0111] Three silicone-modified waterborne polyurethane adhesive products were obtained from Example 3-1 to Example 3-4 respectively.

[0112] Dye solution formula: 3wt% liquid disperse red CI167, 8wt% adhesive emulsion, 89wt% deionized water, totaling 100wt%.

[0113] Dyeing process: polyester fabric → spray dyeing → drying (80℃, 2min) → high temperature baking (190℃, 3min) → finished product.

[0114] Under the above conditions, silicone-modified waterborne polyurethane adhesives prepared with different hard segment amounts were used for water-free digital spray dyeing of polyester fabrics to explore the effect of hard segment amount on the surface color gain (K / S), permeability and color fastness to rubbing of dyed fabrics. The results are shown in Table 3.

[0115] Table 3 Effect of different hard segment dosage on the water-free digital dyeing performance of polyester fabric

[0116]

[0117] As can be seen from Table 3, with the increase in the amount of hard segment, the color yield of the spray-dyed fabric did not change significantly, the dry rubbing fastness remained unchanged, and the wet rubbing fastness was improved and remained unchanged. When the hard segment dosage was 8.24g, the color yield of the front and back of the spray-dyed fabric reached 16.25 and 13.30 respectively, and the dry and wet rubbing fastness reached 4-5 and 3-4 respectively.

[0118] Example 4: Comparison of dyeing properties of homemade adhesives, pure dyes and commercially available adhesives

[0119] (1) First, 10.4 g of PBA, 1.2 g of PDMS, and 1 g of DBA were dried in a vacuum oven at 90 °C for 2 h.

[0120] (2) Using 0.006 g of dibutyltin dilaurate as a catalyst, 6.47 g of IPDI, a total of 11.6 g of PBA and PDMS were added into a four-necked flask in sequence, and the temperature was raised to 80° C. under nitrogen protection, and a condensation reaction was carried out for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P1.

[0121] (3) Pour 1 g of DBA into 2.1 g of N-methylpyrrolidone solution to dissolve, then add the solution into a four-necked flask and continue the reaction for 2 h to obtain a silicone-modified waterborne polyurethane prepolymer P2. During the reaction, observe the change in the viscosity of the system, and add an appropriate amount of acetone to reduce the viscosity.

[0122] (4) The temperature was initially lowered to 70°C, 0.77 g of BDO was added, and the chain extension reaction was continued for 1.5 h.

[0123] (5) The temperature was lowered to 60°C again, and 1.57 g of 2-butanone oxime was added to carry out the end-capping reaction for 2 h. Samples were taken at intervals and monitored by infrared spectroscopy until the characteristic peak of the NCO group completely disappeared.

[0124] (6) Finally, the temperature was lowered to 40° C., 0.68 g of triethylamine was added for neutralization, and then 49 g of deionized water was added. The mixture was emulsified at a speed of 800 rpm for 1 h, and rotary evaporated at 40° C. to obtain a silicone-modified waterborne polyurethane emulsion.

[0125] The polyester fabric is digitally spray-dyed using dye ink prepared by using the organosilicon-modified water-based polyurethane adhesive and liquid disperse dye.

[0126] Dye solution formula: 3wt% liquid disperse red CI167, adhesive emulsion, deionized water, totaling 100wt%.

[0127] Dyeing process: polyester fabric → spray dyeing → drying (80℃, 2min) → high temperature baking (190℃, 3min) → finished product.

[0128] Under the above conditions, the dye ink with different amounts of homemade silicone-modified waterborne polyurethane adhesive was used for water-free digital jet dyeing of polyester fabric. The results of color yield (K / S), permeability and color fastness to rubbing of the dyed fabric are shown in Table 4.

[0129] Table 4 Effect of the dosage of silicone-modified waterborne polyurethane on the digital dyeing properties of polyester fabrics

[0130]

[0131] As can be seen from Table 4, compared with fabrics spray-dyed with pure dyes, the homemade silicone-modified water-based polyurethane adhesive can significantly increase the color yield of spray-dyed fabrics, increase the dry rubbing color fastness by 2 levels, and increase the wet rubbing color fastness by 1 level.

Claims

1. A water-free digital dyeing adhesive with disperse dye unidirectional delivery function, characterized in that: The structure of the water-free digital dyeing adhesive is as follows:

2. A method for preparing a water-free digital dyeing adhesive having a disperse dye unidirectional delivery function as claimed in claim 1, characterized in that: include: Polybutylene adipate-1,4-diol, hydroxyl-terminated polysilane and a corresponding amount of isophorone diisocyanate are subjected to polycondensation reaction under the action of a catalyst to obtain an organosilicon-modified waterborne polyurethane prepolymer P1; 2,2-dihydroxymethylbutyric acid is added to continue the polycondensation reaction with P1 and a corresponding amount of isophorone diisocyanate to obtain an organosilicon-modified waterborne polyurethane prepolymer P2; 1,4-butanediol is then added to carry out a chain extension reaction with P2 and a corresponding amount of isophorone diisocyanate; finally, 2-butanone oxime is used for end-capping; and post-treatment is performed to obtain the water-free digital dyeing adhesive with a disperse dye unidirectional delivery function.

3. The method for preparing the water-free digital dyeing adhesive having the disperse dye unidirectional delivery function according to claim 2, characterized in that: The following steps are involved: (1) first drying poly(1,4-butylene adipate), hydroxyl-terminated polysiloxane, and 2,2-dimethylolbutyric acid in a vacuum oven at 70-90° C. for 1-3 h; (2) using dibutyltin dilaurate as a catalyst, adding isophorone diisocyanate, poly(1,4-butylene adipate) and hydroxyl-terminated polyoxysilane into a reaction vessel in sequence, protecting with nitrogen, heating to 75-85° C., and performing polycondensation reaction for 1-3 hours to obtain a silicone-modified waterborne polyurethane prepolymer P1; (3) dissolving 2,2-dihydroxymethylbutyric acid in N-methylpyrrolidone, and then adding the solution to the reaction vessel of step (2), and continuing the reaction at 75-85° C. for 1-3 hours to obtain a silicone-modified waterborne polyurethane prepolymer P2; during the reaction, the viscosity of the system is appropriately controlled; (4) Initially cool down to 65-75°C, add 1,4-butanediol, and carry out chain extension reaction for 1-2h; (5) cooling again to 55-65°C, adding 2-butanone oxime to carry out end-capping reaction for 2-4 hours; (6) Finally, the temperature is lowered to 35-45° C., triethylamine is added for neutralization, and then deionized water is added for high-speed emulsification for 0.5-1.5 h to remove part of the solvent to obtain a silicone-modified waterborne polyurethane emulsion.

4. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 2 or 3, characterized in that: The molecular weight of poly(1,4-butylene adipate) is 1500-3000, and the molecular weight of hydroxyl-terminated polyoxysilane is 500-1500.

5. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 2 or 3, characterized in that: In the reaction monomer, the molar ratio of isocyanate groups to total active hydroxyl groups, i.e., the chain extension coefficient R value is (1.0-1.7):

1.

6. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 2 or 3, characterized in that: In the synthetic monomers, isophorone diisocyanate, 2,2-dihydroxymethylbutyric acid and 1,4-butanediol account for 34-46% of the total weight of the monomers.

7. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 2 or 3, characterized in that: The mass of the isophorone diisocyanate accounts for 25-36% of the total mass of the monomers, the mass of the poly(1,4-butylene adipate) accounts for 48-62% of the total mass of the monomers, the mass of the hydroxyl-terminated polyoxysilane accounts for 2-11% of the total mass of the monomers, the mass of the 2,2-dihydroxymethylbutyric acid accounts for 4-6% of the total mass of the monomers; the mass of the 1,4-butylene glycol accounts for 1.5-6% of the total mass of the monomers; and the mass of the catalyst dibutyltin dilaurate accounts for 0.02-0.04% of the total mass of the monomers.

8. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 2 or 3, characterized in that: The mass of the N-methylpyrrolidone is 200-220% of the mass of the 2,2-dihydroxymethylbutyric acid; the triethylamine accounts for 3-6% of the total mass of the monomer; and the added amount of deionized water accounts for 186-300% of the total mass of the monomer.

9. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 2 or 3, characterized in that: The amount of 1,2-butanone oxime added is calculated based on the number of moles of the remaining unreacted isocyanate groups.

10. The method for preparing the water-free digital dyeing adhesive with disperse dye unidirectional delivery function according to claim 3, characterized in that: The emulsification speed is 750-850 rpm, and the emulsification time is 0.5-1.5 h. The rotary evaporation method is used to remove part of the solvent. The rotary evaporation temperature is 35-45° C., and the rotary evaporation time is 0.5-1.5 h.

Images