Low-staining low-viscosity waterborne polyurethane macromolecular coloring agent and preparation method thereof

Abstract

The invention discloses a low-staining low-viscosity waterborne polyurethane macromolecular coloring agent and a preparation method of the low-staining low-viscosity waterborne polyurethane macromolecular coloring agent. Comprising the following components in parts by weight: 15 to 30 parts of aliphatic diisocyanate, 15 to 30 parts of micromolecular dye, 10 to 30 parts of polypropylene glycol and / or dihydroxy silicone oil, 25 to 50 parts of polyethylene glycol, 1 to 3 parts of micromolecular dihydroxy compound chain extender, 0.05 to 0.3 part of catalyst, 90 to 140 parts of acetone and 50 to 300 parts of water. By designing the hydrophilicity and proportion of the soft and hard segments of the polyurethane coloring agent, the waterborne polyurethane macromolecular coloring agent color paste which is low in staining, easy to clean, less than 1000mpas in product viscosity, more than 5% in color concentration and more than 5% in dye equivalent and good in compatibility is finally obtained, and the waterborne polyurethane macromolecular coloring agent color paste can meet the requirements of liquid product coloring agents such as clothing care and household cleaning agents. The cleaning agent can also be used for liquid cleaning agent products for body care and catering.

Description

Technical Field

[0001] The present invention relates to the technical field of colorants, and particularly relates to a low-staining and low-viscosity aqueous polyurethane macromolecular colorant and a preparation method thereof. Background Art

[0002] Daily chemical cleaning agents include washing powder, laundry detergent, laundry beads, shampoo, and hand sanitizer, etc. They need to come into contact with the skin during daily use, and a mild and easily washable colorant is required. Currently, a large number of macromolecular colorants in use are obtained by ring-opening polymerization of some acidic or reactive dyes with active groups through epoxy. These polyether macromolecular dyes have weak staining, are easy to wash, and do not irritate the skin, but they are extremely expensive; and epoxy ring-opening is a dangerous process with a high risk of explosion. Moreover, the epoxy ring-opening activity of dye molecules is relatively low, and the polymerization is difficult, requiring high temperature, special catalysts, and preparation processes. The risk and cost are both higher compared to ordinary epoxy ring-opening; and in order to keep the dye color concentration not too low and control the viscosity of the colorant product, its overall molecular weight is relatively small (within 2000 in number-average molecular weight). When there is a certain molecular weight distribution, there will inevitably be some small-molecular-weight polyether dyes, which may pose certain potential safety hazards to the skin of people in contact.

[0003] Regarding aqueous macromolecular colorants of polyurethane type, there have been some reports, which are achieved through stepwise addition polymerization of diisocyanates with easy-to-control reaction activity and polymerization degree, dihydroxylated dyes, and hydrophilic chain extenders. The preparation process is relatively safe, and it is easy to obtain aqueous polymer colorants with high molecular weight and high color concentration.

[0004] However, the staining property and viscosity of the currently reported polyurethane macromolecular colorants still cannot meet the requirements for the application of daily chemical cleaning agents. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the technical defects in the background art and provide a low-staining and low-viscosity aqueous polyurethane macromolecular colorant and a preparation method thereof. The present invention provides a class of non-ionic aqueous macromolecular colorants with non-staining and low viscosity for daily chemical washing and care, specifically the aqueous dispersion of polyurethane-type macromolecular dyes; by designing the hydrophilicity and ratio of the hard and soft segments of the polyurethane colorant, an aqueous polyurethane macromolecular colorant slurry with low staining, easy to wash, a product viscosity below 1000 mPas, a color concentration above 5% dye equivalent, and good compatibility is finally obtained, which can meet the requirements of colorants for liquid products including clothing care and household cleaning agents, and can also be used for body care and food service liquid cleaning agent products.

[0006] The technical solutions adopted by the present invention to solve the above technical problems are as follows: A low-staining and low-viscosity aqueous polyurethane macromolecular colorant, by weight, comprises the following components: 15-30 parts of aliphatic diisocyanate, 15-30 parts of small molecule dye, 10-30 parts of polypropylene glycol and / or dihydroxy silicone oil, 25-50 parts of polyethylene glycol, 1-3 parts of small molecule dihydroxy compound chain extender, 0.05-0.3 parts of catalyst, 90-140 parts of acetone, and 50-300 parts of water.

[0007] Preferably, the aliphatic diisocyanate is any one or more of isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and methylcyclohexyl diisocyanate.

[0008] Preferably, the small molecule dye is a dihydroxy or diamino dye; the dihydroxy or diamino dye can be selected from any dye molecule with two hydroxyl functional groups, including one or more of the following chromophores: azo, azo metal complex, phthalocyanine, anthraquinone, azacrown

[18] , formazane-copper-complex, triaryldioxazine, nitroso, nitro, diarylmethane, triarylmethane, xanthene, acridine, methylene, thiazole, indamine, azine, oxazine, thiazine, quinoline, indigo, indophenol, lactone, aminoketone, hydroxyketone, and stilbene.

[0009] More preferably, the small molecule dye is selected from one or more of Color Index (Society of Dyers and Colourists, Bradford, UK) No.: C.I. Disperse Red 4, C.I. Disperse Red 5, C.I. Disperse Red 7, C.I. Disperse Red 11, C.I. Disperse Red 15, C.I. Disperse Red 17, C.I. Disperse Red 19, C.I. Disperse Red 30, C.I. Disperse Red 58, C.I. Disperse Red 60, C.I. Disperse Red 64, C.I. Disperse Red 107, C.I. Disperse Red 118, C.I. Disperse Yellow 4, C.I. Disperse Yellow 6, C.I. Disperse Yellow 104, C.I. Disperse Yellow 123, C.I. Disperse Yellow 68, C.I. Disperse Blue 1, C.I. Disperse Blue 7, C.I. Disperse Blue 23, C.I. Disperse Blue 60, C.I. Disperse Blue 96, C.I. Disperse Blue 99, C.I. Disperse Blue 128, C.I. Disperse Blue 143, C.I. Disperse Blue 176, C.I. Disperse Green 5, C.I. Disperse Brown 1, C.I. Disperse Brown 4, C.I. Disperse Black 1, C.I. Disperse Black 2, C.I. Disperse Black 6, C.I. Disperse Black 27, C.I. Disperse Violet 1, C.I. Disperse Violet 8, C.I. Disperse Violet 26, C.I. Disperse Violet 28, C.I. Disperse Violet 35, C.I. Disperse Violet 38, C.I. Disperse Violet 43, C.I. Disperse Violet 46, C.I. Disperse Violet 62, alizarin, curcumin, indigo, shikonin, C.I. Basic Yellow 5, C.I. Basic Red 2, etc., and one or several of those falling into Direct Violet 9, Direct Violet 35, Direct Violet 48, Direct Violet 51, Direct Violet 66, Direct Violet 99, Direct Blue 1, Direct Blue 71, Direct Blue 80, Direct Blue 279, Acid Red 17, Acid Red 52, Acid Red 73, Acid Red 88, Acid Red 150, Acid Violet 15, Acid Violet 17, Acid Violet 24, Acid Violet 43, Acid Red 52, Acid Violet 49, Acid Violet 50, Acid Blue 15, Acid Blue 17, Acid Blue 25, Acid Blue 29, Acid Blue 40, Acid Blue 45, Acid Blue 75, Acid Blue 80, Acid Blue 83, Acid Blue 90, Acid Blue 113, Acid Black 1, Basic Violet 1, Basic Violet 3, Basic Violet 4, Basic Violet 10, Basic Violet 35, Basic Blue 3, Basic Blue 16, Basic Blue 22, Basic Blue 47, Basic Blue 66, Basic Blue 75, Basic Blue 159.

[0010] Preferably, the molecular weight of the polypropylene glycol is 200 - 5000, more preferably 400 - 3000.

[0011] Preferably, the dihydroxy silicone oil is a linear hydroxyl - type methyl silicone oil at both ends or a branched - chain di - hydroxyl silicone oil, with a molecular weight of 300 - 6000, more preferably 500 - 3000.

[0012] Preferably, the molecular weight of the polyethylene glycol is 200 to 10,000, more preferably 400 to 4,000.

[0013] Preferably, the small molecule dihydroxy compound chain extender is any one or more of ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol.

[0014] Preferably, the catalyst is an organotin or an organobismuth; the organotin can be a catalyst for conventional polyurethane synthesis, such as any one of stannous octoate, dibutyltin diacetate, and dibutyltin dilaurate.

[0015] The preparation method of the low staining and low viscosity aqueous polyurethane macromolecular colorant as described above includes the following steps: (1) Dehydrate the polyethylene glycol. (2) Disperse 10 to 30 parts of polypropylene glycol and / or dihydroxy silicone oil and 0.05 to 0.3 part of catalyst into 15 to 30 parts of aliphatic diisocyanate, raise the temperature, carry out a reflux reaction, then add 25 to 50 parts of polyethylene glycol and continue the reaction. During this period, add 10 to 20 parts of acetone to adjust the viscosity of the reaction solution, and then add 15 to 30 parts of small molecule dye and 80 to 120 parts of acetone solvent, and continue the reaction to complete the prepolymerization. (3) Add 1 to 3 parts of small molecule dihydroxy compound chain extender, and supplement an appropriate amount of small molecule dihydroxy compound chain extender according to the degree of polymerization, extend the reaction time, so that the degree of polymerization reaches 99.5% to 99.9%, and a polyurethane macromolecular colorant with a number average molecular weight of more than 5,000 and a molecular weight of more than 3,000 and more than 99% can be obtained. (4) Slowly inject the obtained polymer colorant into 50 to 300 parts of water under rapid stirring for shear emulsification after cooling, and then remove the acetone solvent under reduced pressure to finally obtain a finished product of a low staining and low viscosity aqueous polyurethane macromolecular colorant slurry.

[0016] Preferably, in step (1), the polyethylene glycol is dehydrated for 2 to 3 hours under the conditions of 100 to 110 °C and a vacuum degree ≤ 0.1 MPa.

[0017] Preferably, in step (2), the temperature is raised to 65 to 75 °C for reflux reaction for 1 to 2 h.

[0018] Preferably, in step (2), then add 25 to 50 parts of polyethylene glycol and continue the reaction for 1 to 2 h.

[0019] Preferably, in step (2), continue the reaction for 2 to 3 h to complete the prepolymerization.

[0020] Preferably, in step (3), add 1 to 3 parts of small molecule dihydroxy compound chain extender and react for 2 to 3 h.

[0021] Preferably, in step (4), the obtained polymer colorant is cooled to 40-50 °C.

[0022] Preferably, in step (4), the time for shear emulsification is 30 min.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses polyether diol commonly used in the daily chemical field as the main component, which is not only low in price, but also mild in composition and good in formulation compatibility. The present invention uses dihydroxy dye as the hard segment component, and polypropylene glycol or silicone diol as the soft segment component, etc., as the hydrophobic chain segment together, and polyethylene glycol ether as the non-ionic hydrophilic chain segment, and forms a stable low-viscosity aqueous dispersion through water dispersion emulsification. The colorant with different viscosity ranges and color concentrations can be conveniently adjusted by adjusting the solid content of the aqueous dispersion. (2) The macromolecular colorant of the present invention does not use amine compounds, as much as possible eliminates the irritation of ammonia compounds and reduces the staining property, and at the same time controls the isocyanate content at a low level to further reduce the staining property; it is not capped with a capping agent, and the residue of small molecules is reduced as much as possible to ensure low irritation. (3) The aqueous polyurethane macromolecular colorant of the present invention ensures that the molecular weight of the macromolecular colorant is above 3000 by 99%, reduces the content of small molecules, reduces the staining, has high mildness, and can be used in various detergents or care agents in contact with the human body, including laundry detergent, laundry beads, hand sanitizer, shampoo, and body wash. Description of the Drawings

[0024] Figure 1 It is the GPC test chart of the aqueous polyurethane macromolecular colorant synthesized in Example 1 of the present invention (calibrated molecular weight upper limit retention time: 8.22 min, calibrated molecular weight measurement retention time: 10.77 min, calibrated molecular weight upper limit: 217878, calibrated molecular weight lower limit: 1179); Figure 2 It is the GPC test chart of the aqueous polyurethane macromolecular colorant synthesized in Example 2 of the present invention (calibrated molecular weight upper limit retention time: 8.22 min, calibrated molecular weight measurement retention time: 10.77 min, calibrated molecular weight upper limit: 217878, calibrated molecular weight lower limit: 1179); Figure 3 It is the GPC test chart of the aqueous polyurethane macromolecular colorant synthesized in Example 3 of the present invention (calibrated molecular weight upper limit retention time: 8.24 min, calibrated molecular weight measurement retention time: 10.81 min, calibrated molecular weight upper limit: 217497, calibrated molecular weight lower limit: 1178); Figure 4GPC test chart of the waterborne polyurethane macromolecular colorant synthesized in Example 4 of the present invention (retention time of the calibrated molecular weight upper limit: 8.24 min, retention time of the calibrated molecular weight measurement: 10.81 min, calibrated molecular weight upper limit: 217494, calibrated molecular weight lower limit: 1178); Figure 5 GPC test chart of the waterborne polyurethane macromolecular colorant synthesized in Example 5 of the present invention (retention time of the calibrated molecular weight upper limit: 8.24 min, retention time of the calibrated molecular weight measurement: 10.81 min, calibrated molecular weight upper limit: 217497, calibrated molecular weight lower limit: 1178); Figure 6 GPC test chart of the waterborne polyurethane macromolecular colorant synthesized in Example 6 of the present invention (retention time of the calibrated molecular weight upper limit: 8.17 min, retention time of the calibrated molecular weight measurement: 10.72 min, calibrated molecular weight upper limit: 217791, calibrated molecular weight lower limit: 1179); Figure 7 GPC test chart of the waterborne polyurethane macromolecular colorant synthesized in Comparative Example 5 of the present invention (retention time of the calibrated molecular weight upper limit: 8.15 min, retention time of the calibrated molecular weight measurement: 10.70 min, calibrated molecular weight upper limit: 217576, calibrated molecular weight lower limit: 1178); Figure 8 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Example 1 of the present invention; Figure 9 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Example 2 of the present invention; Figure 10 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Example 3 of the present invention; Figure 11 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Example 4 of the present invention; Figure 12 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Example 5 of the present invention; Figure 13 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Example 6 of the present invention; Figure 14 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Comparative Example 1 of the present invention; Figure 15 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Comparative Example 2 of the present invention; Figure 16 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Comparative Example 3 of the present invention; Figure 17 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Comparative Example 4 of the present invention; Figure 18 Staining test effect diagram of the waterborne polyurethane macromolecular colorant synthesized in Comparative Example 5 of the present invention. Detailed implementation manners

[0025] To better understand the content of the present invention, the following further explains with specific embodiments and drawings. It should be understood that these embodiments are only used to further illustrate the present invention, rather than limiting the scope of the present invention. In addition, it should be understood that after reading the content described in the present invention, those skilled in the art make some non-essential changes or adjustments to the present invention, which still fall within the protection scope of the present invention.

[0026] Example 1 C.I. Disperse Violet 43 Mw: 434.53 A preparation method of a low-staining and low-viscosity waterborne polyurethane macromolecular colorant is as follows: (1) Polyethylene glycol 1000 is dehydrated at 100-110°C under a vacuum of ≤0.1 MPa for 2-3 hours; (2) 16 parts of polypropylene glycol 600 and 0.1 part of dibutyltin diacetate are dispersed into 21.7 parts of hexamethylene diisocyanate, and the temperature is raised to 65-75°C for reflux reaction for 1-2 h. Then 39 parts of polyethylene glycol 1000 are added and the reaction continues for 1-2 h. During this period, 10-20 parts of acetone are added to adjust the viscosity of the reaction solution. Then 22 parts of C.I. Disperse Violet 43 and 100 parts of acetone solvent are added, and the reaction continues for 2-3 h to complete the prepolymerization; (3) 2 parts of diethylene glycol chain extender are added and the reaction is carried out for 2 h. Depending on the degree of polymerization, an appropriate amount of diethylene glycol chain extender is added to extend the reaction time to make the degree of polymerization reach 99.5%-99.9%; (4) The obtained polymer colorant is cooled to 40-50°C and then slowly injected into 100 parts of normal-temperature water under rapid stirring for shear emulsification for 30 min. Then the acetone solvent is removed by reduced pressure evaporation. Finally, a low-staining and low-viscosity waterborne polyurethane macromolecular colorant paste product is obtained. The GPC test results are shown in Figure 1 , showing that its number-average molecular weight is 15935 and there is no small molecule peak with a molecular weight lower than 1179.

[0027] Example 2 C.I. Disperse Red 12 Mw 411.9 A preparation method of a low-staining and low-viscosity waterborne polyurethane macromolecular colorant is as follows: (1) Dehydrate polyethylene glycol 1500 at 100 - 110°C under a vacuum of ≤0.1 MPa for 2 - 3 hours; (2) Disperse 17 parts of dihydroxy silicone oil 1000 and 0.1 part of dibutyltin dilaurate into 19 parts of isophorone diisocyanate, heat up to 65 - 75°C and reflux for 1 - 2 h, then add 48 parts of polyethylene glycol 1500 and continue to react for 1 - 2 h. During this period, add 10 - 20 parts of acetone to adjust the viscosity of the reaction solution. After that, add 15 parts of C.I. Disperse Red 12 and 100 parts of acetone solvent, and continue to react for 2 - 3 h to complete prepolymerization; (3) Add 1.5 parts of 1,4 - butanediol chain extender and react for 2 h. Supplement an appropriate amount of 1,4 - butanediol according to the degree of polymerization and extend the reaction time to make the degree of polymerization reach 99.5% - 99.9%; (4) Cool the obtained polymer colorant to 40 - 50°C and then slowly inject it into 100 parts of rapidly stirred normal - temperature water for shear emulsification for 30 min. After that, remove the acetone solvent under reduced pressure to finally obtain a low - staining and low - viscosity aqueous polyurethane macromolecular colorant color paste product. The GPC test results are shown in Figure 2 , showing that its number - average molecular weight is 12504 and there is no small - molecule peak with a molecular weight lower than 1179.

[0028] Example 3 C.I. Disperse Yellow 4 Mw265.27 A preparation method of a low - staining and low - viscosity aqueous polyurethane macromolecular colorant is as follows: (1) Dehydrate polyethylene glycol 1000 at 100 - 110°C under a vacuum of ≤0.1 MPa for 2 - 3 hours; (2) Disperse 12 parts of polypropylene glycol 400 and 0.1 part of stannous octoate into 30 parts of isophorone diisocyanate, heat up to 65 - 75°C and reflux for 1 - 2 h, then add 38 parts of polyethylene glycol 1000 and continue to react for 1 - 2 h. During this period, add 20 parts of acetone to adjust the viscosity of the reaction solution. After that, add 18 parts of C.I. Disperse Yellow 4 and 110 parts of acetone solvent, heat up to 80°C and continue to reflux for 2 - 3 h to complete prepolymerization; (3) Add 1 part of ethylene glycol chain extender and react for 2 h. Supplement an appropriate amount of ethylene glycol chain extender according to the degree of polymerization and extend the reaction time to make the degree of polymerization reach 99.5% - 99.9%; (4) Cool the obtained polymer colorant to 40 - 50°C and then slowly inject it into 100 parts of rapidly stirred normal - temperature water for shear emulsification for 30 min. After that, remove the acetone solvent under reduced pressure to finally obtain a low - staining and low - viscosity aqueous polyurethane macromolecular colorant color paste product. The GPC test results are shown in Figure 3 , showing that its number - average molecular weight is 10098 and there is no small - molecule peak with a molecular weight lower than 1178.

[0029] Example 4 C.I. Disperse Blue 60 Mw: 379.37 A preparation method of a low-staining and low-viscosity aqueous polyurethane macromolecular colorant is as follows: (1) Polyethylene glycol 2000 is dehydrated at 100 - 110 °C under a vacuum of ≤ 0.1 MPa for 2 - 3 hours; (2) 20 parts of polypropylene glycol 1000 and 0.1 part of dibutyltin dilaurate are dispersed in 19.5 parts of hexamethylene diisocyanate, heated to 65 - 75 °C and refluxed for 1 - 2 h, then 40.5 parts of polyethylene glycol 2000 are added and the reaction continues for 1 - 2 h. During this period, 15 parts of acetone are added to adjust the viscosity of the reaction solution. Then 18.7 parts of C.I. Disperse Blue 60 and 110 parts of acetone solvent are added, and the reaction continues for 2 - 3 h to complete the prepolymerization; (3) 1 part of diethylene glycol chain extender is added and the reaction is carried out for 2 h. Appropriate amount of diethylene glycol chain extender is added according to the degree of polymerization, and the reaction time is extended to make the degree of polymerization reach 99.5% - 99.9%; (4) The obtained polymer colorant is cooled to 40 - 50 °C and then slowly injected into 100 parts of normal-temperature water under rapid stirring for shear emulsification for 30 min. Then the acetone solvent is removed by reduced pressure distillation, and finally a low-staining and low-viscosity aqueous polyurethane macromolecular colorant paste product is obtained. The GPC test results are shown in Figure 4 , showing that its number-average molecular weight is 10681 and there is no small molecule peak with a molecular weight lower than 1178.

[0030] Example 5 Diethanolamine-modified C.I. Acid Blue 15 Mw: 807.26 A preparation method of a low-staining and low-viscosity aqueous polyurethane macromolecular colorant is as follows: (1) Polyethylene glycol 1000 is dehydrated at 100 - 110 °C under a vacuum of ≤ 0.1 MPa for 2 - 3 hours; (2) 20.4 parts of polypropylene glycol 1000 and 0.1 part of dibutyltin diacetate are dispersed in 16 parts of hexamethylene diisocyanate, heated to 65 - 75 °C and refluxed for 1 - 2 h, then 38 parts of polyethylene glycol 1000 are added and the reaction continues for 1 - 2 h. During this period, 15 parts of acetone are added to adjust the viscosity of the reaction solution. Then 24.7 parts of diethanolamine-modified C.I. Acid Blue 15 and 110 parts of acetone solvent are added, and the reaction continues for 2 - 3 h to complete the prepolymerization; (3) 1 part of neopentyl glycol chain extender is added and the reaction is carried out for 2 h. Appropriate amount of neopentyl glycol chain extender is added according to the degree of polymerization, and the reaction time is extended to make the degree of polymerization reach 99.5% - 99.9%; (4) After cooling the obtained polymer colorant to 40 - 50 °C, it was slowly injected into 100 parts of water at room temperature under rapid stirring and sheared for emulsification for 30 min. Then, the acetone solvent was removed by reduced pressure distillation, and finally, a finished product of a low-staining and low-viscosity aqueous polyurethane macromolecular colorant paste was obtained. The GPC test results are shown in Figure 5 , showing that its number-average molecular weight is 11221 and there is no small molecule peak with a molecular weight lower than 1178.

[0031] Example 6 Ethanolamine-modified C.I. Reactive Blue 15 Mw: 1355.7 A preparation method of a low-staining and low-viscosity aqueous polyurethane macromolecular colorant, the steps are as follows: (1) Polyethylene glycol 600 was dehydrated at 100 - 110 °C under a vacuum of ≤0.1 MPa for 2 - 3 hours; (2) 27.4 parts of polypropylene glycol 1500 and 0.1 part of dibutyltin dilaurate were dispersed in 15.4 parts of hexamethylene diisocyanate, and the temperature was raised to 65 - 75 °C for reflux reaction for 1 - 2 h. Then, 28 parts of polyethylene glycol 600 were added and the reaction continued for 1 - 2 h. During this period, 15 parts of acetone were added to adjust the viscosity of the reaction solution. Then, 30 parts of ethanolamine-modified C.I. Reactive Blue 15 and 110 parts of acetone solvent were added, and the reaction continued for 2 - 3 h to complete the prepolymerization; (3) 1 part of 1,6-hexanediol chain extender was added and reacted for 2 h. Appropriate amount of 1,6-hexanediol chain extender was added as needed according to the degree of polymerization, and the reaction time was extended to make the degree of polymerization reach 99.5% - 99.9%; (4) After cooling the obtained polymer colorant to 40 - 50 °C, it was slowly injected into 100 parts of water at room temperature under rapid stirring and sheared for emulsification for 30 min. Then, the acetone solvent was removed by reduced pressure distillation, and finally, a finished product of a low-staining and low-viscosity aqueous polyurethane macromolecular colorant paste was obtained. The GPC test results are shown in Figure 6 , showing that its number-average molecular weight is 28023 and there is no small molecule peak with a molecular weight lower than 1179.

[0032] Comparative Example 1 Compared with Example 1, step (2) was changed to directly mix all the materials for reaction, and the proportions of other components and subsequent steps were the same.

[0033] Comparative Example 2 Compared with Example 1, polypropylene glycol 600 was removed and the corresponding proportion of diisocyanate was reduced, and the others were the same.

[0034] Comparative Example 3 Compared with Example 1, steps (1) - (3) were the same. Step (4) was changed to directly add water and stir for dispersion after the reaction, and then the acetone solvent was removed.

[0035] Comparative Example 4 Compared with Example 1, the amount of diisocyanate in Example 1 was increased to 32 parts, and at the same time, the amount of diethylene glycol chain extender was increased to make the final degree of polymerization between 99.5% and 99.9%, and the others remained unchanged.

[0036] Comparative Example 5 Compared with Example 1, the degree of polymerization in Example 1 was controlled to 99% to end the reaction, and the rest of the steps were the same. The GPC test results of the prepared macromolecular colorant are shown in Figure 7 , showing that its number-average molecular weight is 5181, and there is a large proportion of small molecule peaks with molecular weights lower than 1178.

[0037] Application Example The color values of the above examples and comparative examples were adjusted to be consistent according to the color system, and then two ten-thousandths of the dye was added to the base material of a certain brand of laundry detergent to make a finished laundry detergent, and the following staining test was carried out on the finished laundry detergent.

[0038] Staining test: Soak a six-fiber cloth with a length of 8 cm and a width of 1 cm in the base material for 4 hours, take it out and rub it repeatedly under tap water for 1 minute, and observe whether there is staining on the six-fiber cloth after drying for 2 hours.

[0039] The application test results are shown in the following table: \ Color Average molecular weight Color content Viscosity (mpa.s) Viscosity after storing at room temperature for 30 days (mpa.s) Color staining (test addition amount is two ten-thousandths) Example 1 Rose red 15935 11% 317 323 Excellent (see Figure 8 ) Example 2 Scarlet red 12504 7.50% 539 551 Excellent (see Figure 9 ) Example 3 Bright yellow 10098 9% 266 272 Excellent (see Figure 10 ) Example 4 Royal blue 10681 9.35% 678 685 Excellent (see Figure 11 ) Example 5 Bright blue 11221 12.35% 496 501 Excellent (see Figure 12 ) Example 6 Jade green 28023 15% 689 694 Excellent (see Figure 13 ) Comparative example 1 Rose red 14749 11% 2571 \ Good (see Figure 14 ) Comparative example 2 Rose red 12858 10.52% 12085 \ Good (see Figure 15 ) Comparative example 3 Rose red 15935 11% 1334 \ Good (see Figure 16 ) Comparative example 4 Rose red 10106 11% 853 \ Difference (see Figure 17 ) Comparative example 5 Rose red 5181 11% 332 \ General (see Figure 18 ) As can be seen from the above table, the number-average molecular weights of the polyurethane colorants with different color structures obtained in each example of the present invention are all higher than 10,000, the color content of the aqueous dispersion is greater than 5%, the viscosity is less than 1000 mPa·s, and it has good storage stability. The staining of the formulated laundry detergent is extremely low and the performance is excellent.

[0040] In Comparative Example 1, the feeding and reaction order of the raw materials were changed. Although the molecular weight of the obtained product did not change significantly, the viscosity increased by one order of magnitude.

[0041] In Comparative Example 2, the polypropylene glycol component was removed, the molecular weight did not change much, but the viscosity increased by two orders of magnitude and became a state of almost non-flow.

[0042] In Comparative Example 3, after the reaction, it was not dispersed and emulsified, but directly mixed with water. Although its viscosity was lower than that of the first two comparative examples, it also exceeded 1000 mPa·s, reflecting the importance of the emulsification process.

[0043] In Comparative Example 4, the proportion of isocyanate was increased by 10.3%, and the staining became significantly more, showing very poor performance. While the first three comparative examples did not change the composition and maintained a low isocyanate content, the staining performance was excellent.

[0044] In Comparative Example 5, the reaction degree was reduced, and obvious small molecules appeared in the molecular weight of the product, and the staining performance was also inferior to that of Example 1.

[0045] The present invention discloses a high-molecular-weight macromolecular colorant for daily chemical use with low staining and low viscosity. It is a non-ionic polyurethane colorant aqueous dispersion, which is prepared by reacting aliphatic isocyanate with polypropylene glycol or dihydroxy silicone oil, polyethylene glycol, dihydroxy / amino dye, and a small-molecule dihydroxy compound chain extender in an acetone solvent in sequence until the degree of polymerization reaches 99.5% - 99.9%, and then injecting water for shear emulsification and removing acetone. The obtained polyurethane colorant aqueous dispersion has a color content of more than 5%, a viscosity of less than 1000 mPa·s, and a content of more than 99% with a molecular weight of more than 2000. When incorporated into the daily chemical base material, it has almost no staining on the surfaces of various materials, and can meet the requirements of colorants for liquid products including clothing care, household cleaning agents, kitchen detergents, and body care.

[0046] The above description is not a limitation of the present invention, nor is the present invention limited to the above examples. Changes, modifications, additions, or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention shall also fall within the protection scope of the present invention.

Claims

1. A low staining and low viscosity aqueous polyurethane macromolecular colorant, characterized in that, By weight, it includes the following components: 15 - 30 parts of aliphatic diisocyanate, 15 - 30 parts of small molecule dye, 10 - 30 parts of polypropylene glycol and / or dihydroxy silicone oil, 25 - 50 parts of polyethylene glycol, 1 - 3 parts of small molecule dihydroxy compound chain extender, 0.05 - 0.3 parts of catalyst, 90 - 140 parts of acetone, and 50 - 300 parts of water.

2. The low staining and low viscosity aqueous polyurethane macromolecular colorant according to claim 1, characterized in that, The aliphatic diisocyanate is any one or more of isophorone diisocyanate, hexamethylene diisocyanate, 4,4 - dicyclohexylmethane diisocyanate, and methylcyclohexyl diisocyanate.

3. The low-staining and low-viscosity aqueous polyurethane macromolecular colorant according to claim 1, wherein, The small molecule dye is a dihydroxy or diamino dye.

4. A low staining and low viscosity aqueous polyurethane macromolecular colorant according to claim 1, characterized in that, The molecular weight of the polypropylene glycol is 200 - 5000.

5. A low-staining and low-viscosity aqueous polyurethane macromolecular colorant according to claim 1, characterized in that, The dihydroxy silicone oil is a linear hydroxy - type methyl silicone oil with two ends or a branched - chain dihydroxy silicone oil, and its molecular weight is 300 - 6000.

6. The low staining and low viscosity aqueous polyurethane macromolecular colorant according to claim 1, characterized in that, The molecular weight of the polyethylene glycol is 200 - 10000.

7. A low-staining and low-viscosity aqueous polyurethane macromolecular colorant according to claim 1, characterized in that, The small molecule dihydroxy compound chain extender is any one or more of ethylene glycol, diethylene glycol, 1,4 - butanediol, neopentyl glycol, and 1,6 - hexanediol.

8. The low staining and low viscosity aqueous polyurethane macromolecular colorant according to claim 1, wherein The catalyst is an organotin or an organobismuth.

9. The preparation method of a low staining and low viscosity aqueous polyurethane macromolecular colorant according to any one of claims 1 to 8, characterized in that, It includes the following steps: (1) Dehydrate the polyethylene glycol. (2) Pre - polymerize the dihydroxy hydrophobic end, hydrophilic segment, and small molecule dye with the diisocyanate in sequence. (3) Add the small molecule dihydroxy compound for chain extension to increase the molecular weight. (4) Add the polymerized macromolecular colorant into water for emulsification to obtain the finished product of macromolecular colorant slurry.

10. The preparation method of a low-staining and low-viscosity aqueous polyurethane macromolecular colorant according to claim 9, characterized in that, In step (1), dehydrate the polyethylene glycol at 100 - 110 °C under a vacuum degree ≤ 0.1 MPa for 2 - 3 hours.

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