阅读说明：本技术 黏胶织物直接染料印花的海藻酸钠/水性聚氨酯复合乳化糊及其制备方法和应用 (Sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabric and preparation method and application thereof ) 是由 周凡雨 彭雄义 崔永明 刘仰硕 董雄伟 李强 蔡亚君 于 2020-12-28 设计创作，主要内容包括：本发明涉及黏胶织物直接染料印花的海藻酸钠/水性聚氨酯复合乳化糊及其制备方法和应用。该乳化糊可由如下方法制得：先制得聚氨酯反应液；再制得接枝聚乙二醇的海藻酸钠反应液；将聚氨酯反应液和接枝聚乙二醇的海藻酸钠反应液混合,制得混合液；将混合液乳化、中和,制得乳液；对乳液脱除溶剂,制得海藻酸钠/水性聚氨酯复合乳化糊。本发明制备的海藻酸钠/水性聚氨酯复合乳化糊用于黏胶织物直接染料印花,制得的印花面料表现为脱糊率高于92%；柔软度好；轮廓清晰度高；渗透率高于85%；耐干摩擦色牢度和皂洗变色牢度等级高等特点,具有很好的应用前景。(The invention relates to a sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, and a preparation method and application thereof. The emulsified paste can be prepared by the following method: firstly, preparing polyurethane reaction liquid; then preparing sodium alginate reaction liquid grafted with polyethylene glycol; mixing the polyurethane reaction solution and the sodium alginate reaction solution grafted with polyethylene glycol to prepare a mixed solution; emulsifying and neutralizing the mixed solution to prepare emulsion; and removing the solvent from the emulsion to prepare the sodium alginate/waterborne polyurethane composite emulsion paste. The sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention is used for direct dye printing of viscose fabrics, and the paste removal rate of the prepared printed fabrics is higher than 92%; the softness is good; the definition of the outline is high; the permeability is higher than 85%; high grade of dry rubbing color fastness and soaping color fastness, and good application prospect.)

1. A preparation method of a sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics is characterized by comprising the following steps:

(1) adding polyethylene glycol and dimethylolpropionic acid into a reaction kettle, dehydrating for 1-2 h in vacuum at 100-120 ℃, slowly cooling to 50-60 ℃, dropwise adding toluene diisocyanate, butanone and catalyst dibutyltin dilaurate, heating to 80-90 ℃, and reacting for 3-4 h; cooling the reaction kettle to 40-45 ℃, and adding monohydroxy acrylic acid for three times in 1-1.5 h; heating to 60-80 ℃, and reacting for 1-2 h under heat preservation; preparing a reaction solution;

(2) adding sodium alginate, 1, 6-hexamethylene diisocyanate, polyethylene glycol and a catalyst dibutyltin dilaurate into a reaction kettle with distilled water, heating to 80-90 ℃, reacting for 3-4 h, and naturally cooling after the reaction is finished to obtain a reaction solution;

(3) stirring and mixing the reaction liquid prepared in the step (1) and the reaction liquid prepared in the step (2) to prepare a mixed liquid; carrying out reverse emulsification on the mixed solution by adopting an emulsification pump with high shear rate, and simultaneously dropwise adding triethylamine for neutralization to prepare emulsion; removing butanone from the emulsion by adopting a reduced pressure low temperature distillation method to prepare the sodium alginate/waterborne polyurethane composite emulsion paste.

2. The preparation method of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics according to claim 1, wherein the molar ratio of the polyethylene glycol, the dimethylolpropionic acid and the toluene diisocyanate is 1: 1-2: 3-5; the using amount of the dibutyltin dilaurate accounts for 0.01-0.1% of the total amount of the monomers, and the volume-to-mass ratio of the butanone (mL) to the total amount of the monomers (g) is 1: 1-3; the molar ratio of the monohydroxy acrylic acid to the dimethylolpropionic acid is 1: 3-5; the molecular weight of the polyethylene glycol is 400, 1000 or 2000.

3. The method for preparing the sodium alginate/aqueous polyurethane composite emulsion paste for direct dye printing of viscose fabric according to claim 1, wherein the dosage ratio of sodium alginate (g), 1, 6-hexamethylene diisocyanate (g), polyethylene glycol (g), dibutyltin dilaurate (g) and distilled water (mL) is as follows: 1: 1 to 2: 3 to 5: 0.1 to 0.3: 100 to 200.

4. The preparation method of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics according to claim 1, wherein the volume ratio of the reaction liquid prepared in the step (1) to the reaction liquid prepared in the step (2) is 1: 0.2-0.4; the shear rate of the emulsifying pump is 6000-15000 r/min.

5. A sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, which is characterized by being prepared by the preparation method of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, according to any one of claims 1 to 4.

6. The use of the sodium alginate/aqueous polyurethane composite emulsion paste for direct dye printing of viscose fabrics as claimed in claim 5, wherein the application method comprises: weighing the dye chemicals according to the color paste prescription, dissolving the direct dye and the sodium chloride by using distilled water, and uniformly mixing to dissolve the direct dye and the sodium chloride; finally, adding the sodium alginate/waterborne polyurethane composite emulsion paste, and uniformly stirring to prepare color paste for direct dye printing of viscose fabric; and printing the prepared color paste on the viscose fabric.

7. The application of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics according to claim 6, wherein the color paste formula is as follows: the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention comprises the following components in percentage by weight: 30-34 g; direct dyes: 2-3 g; sodium chloride: 2-4 g; water was added to 100 g.

8. The use of the sodium alginate/aqueous polyurethane composite emulsion paste for direct dye printing of viscose fabrics according to claim 6, wherein the direct dye is any one of C.I. direct orange 26, C.I. direct yellow 11, C.I. direct blue 6, C.I. direct black 17 and C.I. direct red 31, all of which are named according to the international index number.

9. The application of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics as claimed in claim 6, wherein the printing process comprises the following steps: screen printing (scraping 1 time) → drying (100 ℃, 3min) → steaming (10min) → cold water rinsing 2 times → soaping → cold water washing → drying.

Technical Field

The invention belongs to the technical field of preparation of emulsion paste, and particularly relates to sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabric, and a preparation method and application thereof.

Background

The printing paste is a high molecular compound which has a thickening effect in color paste and can be dispersed in water to prepare a thick colloidal solution with a certain concentration. In the actual printing process of the textile, the paste is a carrier for transferring the dye and the chemicals in the printing paste to the textile and is the main component of the printing paste. Although the factors affecting the printing quality are manifold, the properties of the printing paste determine the final printing effect of the fabric to a large extent and are key factors affecting the printing effect.

The printing paste has four functions in the printing process: firstly, the thickening agent is used as a printing paste, so that the printing paste has certain viscosity, and the bleeding caused by the capillary effect of the fabric is partially offset, thereby ensuring the contour smoothness of the patterns. Secondly, as a dispersing medium and a diluent of dye, chemicals, auxiliary agents and solvents in the printing paste, all components in the printing paste can be uniformly dispersed in the raw paste and diluted to a specified concentration to prepare the printing paste. Thirdly, the dye is used as a transfer agent of the dye and plays a role of a carrier; during printing, dye is transferred to the fabric by means of raw paste, a colored paste film is formed at the pattern position after drying, the dye is transferred and diffused into the fabric through the film during steaming, and the transfer amount of the dye is different according to the type of the paste. Finally, as an adhesive; the paste must have certain adhesive property to the cylinder to ensure that the printing paste is stuck in the concave lines of the cylinder; the color paste is relatively extruded by the cylinder and the pressure roller during printing, so that the color paste can be adhered to the fabric; after drying, the colored paste film on the fabric must have a large drilling capability to the fabric, so that the colored paste film cannot fall off from the fabric.

Currently, pastes for direct dye printing of viscose fabrics are usually prepared by compounding different pastes, and the pastes for compounding include: sodium alginate, starch, emulsified paste, etc. The compounded paste needs to be tried for many times during application, and the optimal paste proportion is sought; the composite paste has the disadvantages of inconvenient application, and in addition, the content of sodium alginate in the composite paste is higher, so that the use cost is increased.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, and the preparation method and the application thereof.

The invention aims to provide a sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, which can be prepared by the following method: reacting polyethylene glycol, dimethylolpropionic acid and toluene diisocyanate under the condition of a catalyst dibutyltin dilaurate, and then adding monohydroxyacrylic acid for chain extension to prepare a polyurethane reaction solution; reacting sodium alginate, 1, 6-hexamethylene diisocyanate and polyethylene glycol under the condition of a catalyst dibutyltin dilaurate to prepare a sodium alginate reaction solution grafted with polyethylene glycol; mixing the polyurethane reaction solution and the sodium alginate reaction solution grafted with polyethylene glycol to prepare a mixed solution; emulsifying and neutralizing the mixed solution to prepare emulsion; and removing the solvent from the emulsion to prepare the sodium alginate/waterborne polyurethane composite emulsion paste.

The invention aims to provide a preparation method of sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, which comprises the following steps:

(1) adding polyethylene glycol and dimethylolpropionic acid into a reaction kettle, dehydrating for 1-2 h in vacuum at 100-120 ℃, slowly cooling to 50-60 ℃, dropwise adding toluene diisocyanate, butanone and catalyst dibutyltin dilaurate, heating to 80-90 ℃, and reacting for 3-4 h; cooling the reaction kettle to 40-45 ℃, and adding monohydroxy acrylic acid for three times in 1-1.5 h; heating to 60-80 ℃, and reacting for 1-2 h under heat preservation; to prepare a reaction solution.

Preferably, the molar ratio of the polyethylene glycol to the dimethylolpropionic acid to the toluene diisocyanate is 1: 1-2: 3-5; the dosage of the dibutyltin dilaurate accounts for 0.01-0.1% of the total amount of the monomers, and the volume-to-mass ratio of butanone (mL) to the total amount of the monomers (g) is 1: 1-3; the molar ratio of the monohydroxy acrylic acid to the dimethylolpropionic acid is 1: 3-5; the molecular weight of the polyethylene glycol is 400, 1000 or 2000.

(2) Adding sodium alginate, 1, 6-hexamethylene diisocyanate, polyethylene glycol and a catalyst dibutyltin dilaurate into a reaction kettle with distilled water, heating to 80-90 ℃, reacting for 3-4 h, and naturally cooling after the reaction is finished to obtain a reaction solution.

Preferably, the sodium alginate (g), the 1, 6-hexamethylene diisocyanate (g), the polyethylene glycol (g), the dibutyltin dilaurate (g) and the distilled water (mL) are used in the following dosage ratios: 1: 1 to 2: 3 to 5: 0.1 to 0.3: 100 to 200.

(3) Stirring and mixing the reaction liquid prepared in the step (1) and the reaction liquid prepared in the step (2) to prepare a mixed liquid; carrying out reverse emulsification on the mixed solution by adopting an emulsification pump with high shear rate, and simultaneously dropwise adding triethylamine for neutralization to prepare emulsion; removing butanone from the emulsion by adopting a reduced pressure low temperature distillation method to obtain the sodium alginate/waterborne polyurethane composite emulsion paste.

Preferably, the volume ratio of the reaction liquid prepared in the step (1) to the reaction liquid prepared in the step (2) is 1: 0.2-0.4; the shear rate of the emulsifying pump is 6000-15000 r/min.

The invention also aims to provide an application of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics, which comprises the following steps: weighing the dye chemicals according to the color paste prescription, dissolving the direct dye and the sodium chloride by using distilled water, and uniformly mixing to dissolve the direct dye and the sodium chloride; finally, adding the sodium alginate/waterborne polyurethane composite emulsion paste, and uniformly stirring to prepare color paste for direct dye printing of viscose fabric; and printing the prepared color paste on the viscose fabric.

Preferably, the color paste formula is as follows: the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention comprises the following components in percentage by weight: 30-34 g; direct dyes: 2-3 g; sodium chloride: 2-4 g; water was added to 100 g.

Preferably, the direct dye is any one of c.i. direct orange 26, c.i. direct yellow 11, c.i. direct blue 6, c.i. direct black 17, c.i. direct red 31, all of which are named by international index numbers.

Preferably, the printing process is as follows: screen printing (scraping 1 time) → drying (100 ℃, 3min) → steaming (10min) → cold water rinsing 2 times → soaping → cold water washing → drying.

The invention has the following remarkable advantages:

(1) the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention has better water solubility, and can well wet fabrics; in addition, the paste forming performance is good; it is well mixed during production and convenient to use.

(2) According to the invention, by regulating the use amounts of sodium alginate and waterborne polyurethane, the composite emulsion paste contains a proper amount of sodium alginate and waterborne polyurethane, so that the purpose that the dye and the chemical auxiliary agent are uniformly dispersed in a colloid system is achieved; when the paste is diluted, the viscosity change of the paste is small; in addition, the paste has certain permeability after being prepared into printing paste, has proper permeability to fabrics, and can permeate into the fabrics.

(3) The examples show that: the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention contains a small amount of sodium alginate, and the performance of the paste is obviously superior to that of pure waterborne polyurethane; when the content of the sodium alginate in the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention is too low, the printing performance of the paste is not improved; however, if the sodium alginate content is too high, the cost of the composite emulsion paste increases.

(4) The sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention is used for direct dye printing of viscose fabrics, and the paste removal rate of the prepared printed fabrics is higher than 92%; the softness is good; the definition of the outline is high; the permeability is higher than 85%; high grade of dry rubbing color fastness and soaping color fastness, and the like, and has good application prospect.

Detailed Description

Direct dye c.i. direct blue 6 was purchased from tianjin shengdati scientific development ltd; printing paste SV-14 was purchased from Xiamen chemical Co., Ltd.

Example 1

The preparation method of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics comprises the following steps:

(1) adding 0.1mol of polyethylene glycol with the molecular weight of 1000 and 0.15mol of dimethylolpropionic acid into a reaction kettle, dehydrating for 1.5h under vacuum at 110 ℃, slowly cooling to 55 ℃, dropwise adding 0.4mol of toluene diisocyanate, 65mL of butanone and 1.3g of catalyst dibutyltin dilaurate, heating to 85 ℃, and reacting for 3.5 h; cooling the reaction kettle to 43 ℃, and adding 0.125mol of monohydroxy acrylic acid into the reaction kettle for three times within 1.2 h; heating to 70 ℃, and reacting for 1.5h under the condition of heat preservation; to prepare a reaction solution.

(2) Adding 1g of sodium alginate, 1.5g of 1, 6-hexamethylene diisocyanate, 4g of polyethylene glycol with the molecular weight of 1000 and 0.2g of catalyst dibutyltin dilaurate into a reaction kettle with 150mL of distilled water, heating to 85 ℃, reacting for 3.5h, and naturally cooling after the reaction is finished to obtain a reaction solution.

(3) Stirring and mixing 100mL of the reaction solution prepared in the step (1) and 30mL of the reaction solution prepared in the step (2) to prepare a mixed solution; carrying out reverse emulsification on the mixed solution by adopting an emulsification pump with the shearing rate of 10000r/min, and simultaneously dropwise adding triethylamine for neutralization to prepare emulsion; removing butanone from the emulsion by adopting a reduced pressure low temperature distillation method to obtain the sodium alginate/waterborne polyurethane composite emulsion paste.

The application of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics comprises the following steps: the color paste formula is selected as follows: the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention comprises the following components in percentage by weight: 32g of a mixture; direct dyes: 2.5 g; sodium chloride: 3g of the total weight of the mixture; water was added to 100 g. Weighing the dye chemicals according to the color paste prescription, dissolving the direct dye and the sodium chloride by using distilled water, and uniformly mixing to dissolve the direct dye and the sodium chloride; finally, adding the sodium alginate/waterborne polyurethane composite emulsion paste, and uniformly stirring to prepare color paste for direct dye printing of viscose fabric; and printing the prepared color paste on the viscose fabric. The printing process comprises the following steps: screen printing (scraping 1 time) → drying (100 ℃, 3min) → steaming (10min) → cold water rinsing 2 times → soaping → cold water washing → drying.

Example 2

The preparation method of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics comprises the following steps:

(1) adding 0.1mol of polyethylene glycol with the molecular weight of 400 and 0.1mol of dimethylolpropionic acid into a reaction kettle, dehydrating for 1.0h in vacuum at the temperature of 100 ℃, slowly cooling to 50 ℃, dropwise adding 0.3mol of toluene diisocyanate, 95.6mL of butanone and 0.478g of catalyst dibutyltin dilaurate, heating to 80 ℃, and reacting for 3.0 h; cooling the reaction kettle to 40 ℃, and adding 0.1mol of monohydroxy acrylic acid into the reaction kettle for three times within 1.0 h; heating to 60 ℃, and reacting for 1.0h under the condition of heat preservation; to prepare a reaction solution.

(2) 1g of sodium alginate, 1.0g of 1, 6-hexamethylene diisocyanate, 3g of polyethylene glycol with the molecular weight of 1000 and 0.1g of catalyst dibutyltin dilaurate are added into a reaction kettle with 100mL of distilled water, the temperature is increased to 80 ℃, the reaction time is 3.0h, and after the reaction is finished, the reaction solution is naturally cooled to prepare the reaction solution.

(3) Stirring and mixing 100mL of the reaction solution prepared in the step (1) and 20mL of the reaction solution prepared in the step (2) to prepare a mixed solution; carrying out reverse emulsification on the mixed solution by adopting an emulsification pump with the shearing rate of 6000r/min, and simultaneously dropwise adding triethylamine for neutralization to prepare emulsion; removing butanone from the emulsion by adopting a reduced pressure low temperature distillation method to obtain the sodium alginate/waterborne polyurethane composite emulsion paste.

The application of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics comprises the following steps: the color paste formula is selected as follows: the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention comprises the following components in percentage by weight: 30g of the total weight of the mixture; direct dyes: 2.0 g; sodium chloride: 2g of the total weight of the mixture; water was added to 100 g. Weighing the dye chemicals according to the color paste prescription, dissolving the direct dye and the sodium chloride by using distilled water, and uniformly mixing to dissolve the direct dye and the sodium chloride; finally, adding the sodium alginate/waterborne polyurethane composite emulsion paste, and uniformly stirring to prepare color paste for direct dye printing of viscose fabric; and printing the prepared color paste on the viscose fabric. The printing process comprises the following steps: screen printing (scraping 1 time) → drying (100 ℃, 3min) → steaming (10min) → cold water rinsing 2 times → soaping → cold water washing → drying.

Example 3

The preparation method of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics comprises the following steps:

(1) adding 0.1mol of polyethylene glycol with molecular weight of 2000 and 0.2mol of dimethylolpropionic acid into a reaction kettle, dehydrating for 2h under vacuum at 120 ℃, slowly cooling to 60 ℃, dropwise adding 0.5mol of toluene diisocyanate, 51.3mL of butanone and 2.3g of catalyst dibutyltin dilaurate, heating to 90 ℃, and reacting for 4 h; cooling the reaction kettle to 45 ℃, and adding 0.2mol of monohydroxy acrylic acid into the reaction kettle for three times within 1.5 h; heating to 80 ℃, and reacting for 2 hours in a heat preservation way; to prepare a reaction solution.

(2) Adding 1g of sodium alginate, 2g of 1, 6-hexamethylene diisocyanate, 5g of polyethylene glycol with the molecular weight of 1000 and 0.3g of catalyst dibutyltin dilaurate into a reaction kettle with 200mL of distilled water, heating to 90 ℃, reacting for 4 hours, and naturally cooling after the reaction is finished to obtain a reaction solution.

(3) Stirring and mixing 100mL of the reaction solution prepared in the step (1) and 40mL of the reaction solution prepared in the step (2) to prepare a mixed solution; carrying out reverse emulsification on the mixed solution by adopting an emulsification pump with the shearing rate of 15000r/min, and simultaneously dropwise adding triethylamine for neutralization to prepare emulsion; removing butanone from the emulsion by adopting a reduced pressure low temperature distillation method to obtain the sodium alginate/waterborne polyurethane composite emulsion paste.

The application of the sodium alginate/waterborne polyurethane composite emulsion paste for direct dye printing of viscose fabrics comprises the following steps: the color paste formula is selected as follows: the sodium alginate/waterborne polyurethane composite emulsion paste prepared by the invention comprises the following components in percentage by weight: 34g of a mixture; direct dyes: 3g of the total weight of the mixture; sodium chloride: 4g of the total weight of the mixture; water was added to 100 g. Weighing the dye chemicals according to the color paste prescription, dissolving the direct dye and the sodium chloride by using distilled water, and uniformly mixing to dissolve the direct dye and the sodium chloride; finally, adding the sodium alginate/waterborne polyurethane composite emulsion paste, and uniformly stirring to prepare color paste for direct dye printing of viscose fabric; and printing the prepared color paste on the viscose fabric. The printing process comprises the following steps: screen printing (scraping 1 time) → drying (100 ℃, 3min) → steaming (10min) → cold water rinsing 2 times → soaping → cold water washing → drying.

Comparative example A

By taking example 1 as a comparison, step (2) is not carried out, i.e. the sodium alginate reaction solution grafted with polyethylene glycol is not prepared, and other preparation methods and application methods are the same as those of example 1.

Comparative example B

By way of comparison with example 1, step (1) was not carried out, i.e.no polyurethane reaction solution was prepared, and the other preparation methods and application methods remained the same as in example 1.

Comparative example C

By taking example 1 as a comparison, the amount of the sodium alginate in the step (2) is reduced from 1g to 0.1g, and other preparation methods and application methods are the same as those in example 1.

Comparative example D

By taking example 1 as a comparison, the amount of the "reaction solution obtained in step (2)" in step (3) was reduced from "30 mL" to "3 mL", and the other preparation methods and application methods were the same as those in example 1.

Comparative example E

Printing paste SV-14 purchased from the market was used as the paste of this example, and a paste was prepared and printed on a viscose fabric by the method of example 1.

And (3) application performance testing:

the pastes obtained in examples 1 to 3 and comparative examples A to E were tested for viscosity using a digital viscometer, print viscosity index (PVI value):wherein eta is₆And η_0.6The viscosity of the paste at 6r/min and 0.6r/min are respectively represented, and the test results are shown in Table 1.

The printed viscose fabrics obtained from examples 1-3 and comparative examples a-E were subjected to the relevant tests: the K/S value is measured by a computer color measuring and matching instrument, and the permeability is measured by the reverse K/S value and the positive K/S value of the fabricThe ratio of the K/S values of the faces; the soaping-resistant color change fastness value test refers to GB/T3921-2008 'textile color fastness test soaping-resistant color fastness'; the dry rubbing fastness value test refers to GB/T3920-2008 'color fastness to rubbing' test for textile color fastness; the formula for calculating the paste removal rate is as follows:m₁m is the mass of the printed and dried fabric₂For the mass of the printed fabric after washing, m₀The quality of the unprinted fabric; and (3) testing the softness of the fabric: testing the softness of the printed fabric on a fabric stylizer; and (3) testing the definition of the contour: evaluating the definition grade according to a visual method; the test results are shown in table 1:

TABLE 1 evaluation of application Properties of sodium alginate/aqueous polyurethane composite emulsion paste for direct dye printing of viscose Fabric

As can be seen from table 1, by comparing example 1 with comparative example a, it can be found that: the sodium alginate grafted with polyethylene glycol has irreplaceable effect on the printing performance of the emulsion paste. By comparing example 1 with comparative example B, it can be found that: polyurethanes have a significant influence on the printing properties of the emulsion pastes. By comparing example 1 with comparative example C, it can be found that: the sodium alginate/waterborne polyurethane composite emulsion paste contains a proper amount of sodium alginate, which is beneficial to the printing performance of the paste; too low a sodium alginate content is detrimental to the printing performance. By comparing example 1 with comparative example D, it can be found that: the sodium alginate/waterborne polyurethane composite emulsion paste contains a proper amount of sodium alginate grafted with polyethylene glycol, so that the printing performance of the paste is facilitated; too low sodium alginate content of the grafted polyethylene glycol is not favorable for printing performance. By comparing examples 1-3 with comparative example E, it can be found that: compared with the commercial printing paste in the market, the sodium alginate/waterborne polyurethane composite emulsion paste and the printed viscose fabric thereof prepared by the invention reach or exceed the commercial printing paste and the printed viscose fabric thereof in the market on a plurality of test index values.