An instant high-viscosity environmentally friendly printing paste and its preparation method

Abstract

The present invention provides an instant high-viscosity environmentally friendly printing paste and a preparation method thereof. The preparation steps are as follows: dissolve sodium alginate, carry out an acetalization reaction between alginic acid and dialdehyde starch under the catalysis of an acid, etc., to make it hydrophobic modified, and obtain a modified alginate-starch paste. After neutralization, ethanol precipitation, drying, pulverization, adding a phosphorus-free chelating dispersant, and packaging, the finished product is obtained. Under the action of a catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction to make sodium alginate hydrophobic modified, remove the hydrophilic hydroxyl groups in the alginate through the reaction, and reduce the agglomeration of the printing paste; through the two aldehyde groups of dialdehyde starch, sodium alginate on different molecular chains can be linked together, effectively increasing the molecular weight of the modified sodium alginate, thereby improving the viscosity of the printing paste and the paste formation rate of the printing paste.

Description

Technical Field

[0001] The present invention belongs to the technical field of printing thickeners, and relates to a quick-dissolving high-viscosity environmentally friendly printing thickener and a preparation method thereof. Background Art

[0002] In printing applications, sodium alginate is an ideal thickener. Its greatest feature is that the preparation of the original paste is convenient, the paste formation rate is high, the color paste stability is good, the color yield is high, the printing permeability is good, the printed color is uniform, the pattern outline is clear, it is easy to wash off from the fabric, and the printed fabric feels soft. Sodium alginate thickener is not only suitable for printing on cotton fabrics, but also suitable for printing on wool, silk, and synthetic fibers.

[0003] Due to the hydrophilic group hydroxyl in its own structure, sodium alginate is prone to agglomeration during dissolution, which in turn affects the dissolution rate. When printing factories use sodium alginate printing thickeners, since workers basically pour them in as a whole during feeding, it is very easy to form agglomerations, resulting in an increase in the dissolution time. Currently, the commonly used solutions are, one is to add salt substances to help the material disperse; the other is to add alcohol substances to help disperse. However, salt substances will increase the difficulty of sewage treatment, and alcohols may cause bubbles during beating, affecting the subsequent printing performance.

[0004] Therefore, there is an urgent need for a quick-dissolving high-viscosity environmentally friendly printing thickener to help printing factories provide printing thickeners with quick dissolution and high paste formation rate on the premise of environmental protection. Summary of the Invention

[0005] The present invention provides a quick-dissolving high-viscosity environmentally friendly printing thickener and a preparation method thereof, and the obtained printing thickener has high viscosity, high paste formation rate, and fast dissolution speed.

[0006] To solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0007] The present invention provides a quick-dissolving high-viscosity environmentally friendly printing thickener, which comprises the following components: modified sodium alginate-starch thickener and phosphorus-free chelating dispersant, and the preparation components of the modified sodium alginate-starch thickener include dialdehyde starch and sodium alginate.

[0008] Preferably, the dialdehyde content of the dialdehyde starch is above 95%, and the viscosity of the 6% mass concentration aqueous solution of dialdehyde starch is 3-20 cps.

[0009] Preferably, the M / G ratio of sodium alginate is 1.5-2.5, and the viscosity of the 1% mass concentration aqueous solution of sodium alginate is 400-800 cps.

[0010] Preferably, the phosphorus-free chelating dispersant includes one or more of trisodium methylglycine diacetate (MGDA), tetrasodium glutamate diacetate (GLDA), tetrasodium dicarboxymethyl aspartate (ASDA), and tetrasodium iminodisuccinate (IDS).

[0011] The present invention also provides a method for preparing a fast-dissolving high-viscosity environmentally friendly printing paste, comprising the following steps:

[0012] (1) Add water to a container and maintain the water temperature at 60-80°C; add dialdehyde starch and sodium alginate and dissolve them to obtain a mixed solution; add 95% ethanol to the mixed solution;

[0013] (2) Add a catalyst to the mixed solution and adjust the pH of the solution to 1-2;

[0014] (3) React the above mixed solution. Under the action of the catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction to hydrophobically modify sodium alginate, obtaining a modified sodium alginate-starch paste;

[0015] (4) After the reaction is completed, add a 10% concentration of NaOH solution to the sodium alginate-starch paste and adjust the pH to 6-8;

[0016] (5) Alcoholize the reaction product, filter, press, granulate, and dry to obtain a granular semi-finished product;

[0017] (6) Grind and screen the granular semi-finished product into irregular particles of 30-80 mesh, and spray and mix with a phosphorus-free chelating dispersant to obtain a fast-dissolving high-viscosity environmentally friendly printing paste.

[0018] Preferably, in step (1), the concentration of the dialdehyde starch is 1-3%, and the concentration of the sodium alginate is 1-2%.

[0019] Preferably, in step (1), the volume ratio of the mixed solution to 95% ethanol is 1:1.

[0020] Preferably, in step (2), the catalyst is one or more of proton acids, including but not limited to one or more of sulfuric acid, hydrochloric acid, trifluoroacetic acid, and boron trifluoride.

[0021] Preferably, in step (3), the reaction is carried out at a temperature of 70-90°C for a reaction time of 10-12 h.

[0022] Preferably, in step (6), the addition amount of the phosphorus-free chelating dispersant is 0.2%-1%.

[0023] Compared with the prior art, the advantages and positive effects of the present invention are as follows: Under the action of a catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction, hydrophobically modifying sodium alginate, removing the hydrophilic hydroxyl groups in the alginate through the reaction, and obtaining a hydrophobically modified sodium alginate-starch paste, thereby reducing the agglomeration of the printing paste. In addition, through the two aldehyde groups of dialdehyde starch, sodium alginate on different molecular chains can be linked together, effectively increasing the molecular weight of the modified sodium alginate, thereby increasing the viscosity of the printing paste and improving the paste-forming rate of the printing paste. By adding an environmentally friendly phosphorus-free chelating dispersant, which is environmentally degradable, divalent metal ions in the glue solution system can be removed to improve the fluidity of the glue solution, and at the same time, it plays a role in dispersing the feedstock, accelerating dissolution, and obtaining a printing paste that dissolves quickly. Detailed Embodiments

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following will further elaborate on the present invention in combination with embodiments. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0025] The present invention provides a quickly dissolving high-viscosity environmentally friendly printing paste, which includes the following components: a modified sodium alginate-starch paste and a phosphorus-free chelating dispersant. The preparation components of the modified sodium alginate-starch paste include dialdehyde starch and sodium alginate.

[0026] The viscosity of an aqueous solution of dialdehyde starch with a mass concentration of 6% is 3-20 cps, and the dialdehyde content of the dialdehyde starch is above 95%, which can ensure the high purity of the dialdehyde starch, ensure that the acetalization reaction between sodium alginate and dialdehyde starch occurs sufficiently, enable the full hydrophobic modification of sodium alginate, and ensure the good hydrophobic modification effect of the obtained sodium alginate-starch paste.

[0027] The viscosity of an aqueous solution of sodium alginate with a mass concentration of 1% is 400-800 cps, and the M / G ratio of sodium alginate is 1.5-2.5. The printing and dyeing effect of the quickly dissolving high-viscosity environmentally friendly printing paste formed therefrom is good, and the film formed by printing is easier to wash off.

[0028] The phosphorus-free chelating dispersant includes one or more of trisodium methylglycine diacetate (MGDA), tetrasodium glutamate diacetate (GLDA), tetrasodium dicarboxymethyl aspartate (ASDA), and tetrasodium iminodisuccinate (IDS); the chelating dispersant used is phosphorus-free and environmentally friendly, and has strong chelating ability, can achieve the chelation of various metal ions, and can also play a role in accelerating dispersion and dissolution, obtaining a printing paste that dissolves quickly.

[0029] The preparation method of the quickly dissolving high-viscosity environmentally friendly printing paste of the present invention includes the following steps:

[0030] (1) Add water to a container and maintain the water temperature at 60 - 80 °C; add dialdehyde starch and sodium alginate and dissolve them to obtain a mixed solution; add 95% ethanol to the mixed solution;

[0031] When the concentration of dialdehyde starch is 1 - 3% and the concentration of sodium alginate is 1 - 2%, it can ensure that a sufficient acetalization reaction occurs between sodium alginate and dialdehyde starch, enabling sufficient hydrophobic modification of sodium alginate and ensuring the acquisition of a sodium alginate - starch paste with good hydrophobic modification effect;

[0032] When the volume ratio of the mixed solution to 95% ethanol is 1:1, it can cause sodium alginate and dialdehyde starch to precipitate and form relatively uniform flocculates, facilitating subsequent reactions and being conducive to obtaining a printing paste that dissolves quickly;

[0033] (2) Add a catalyst to the mixed solution and adjust the pH of the solution to 1 - 2; the catalyst is one or several of proton acids, including but not limited to one or several of sulfuric acid, hydrochloric acid, trifluoroacetic acid, and boron trifluoride.

[0034] (3) React the above - mentioned mixed solution, maintain the temperature at 70 - 90 °C for the reaction, and the reaction time is 10 - 12 h; under the action of the catalyst, an acetalization reaction occurs between sodium alginate and dialdehyde starch, making sodium alginate hydrophobic - modified, removing the hydrophilic hydroxyl groups in the alginate through the reaction, and obtaining a hydrophobic - modified sodium alginate - starch paste, thereby reducing the agglomeration of the printing paste; in addition, through the two aldehyde groups of dialdehyde starch, sodium alginate on different molecular chains can be linked together, effectively increasing the molecular weight of the modified sodium alginate, and thus increasing the viscosity of the printing paste;

[0035] (4) After the reaction is completed, add a 10% concentration of NaOH solution to the sodium alginate - starch paste and adjust the pH to 6 - 8;

[0036] (5) Alcoholize the reaction product, filter, press, granulate, and dry to obtain a granular semi - finished product;

[0037] (6) Grind the granular semi - finished product and screen it into amorphous particles of 30 - 80 mesh, and spray - mix and add a phosphorus - free chelating dispersant to obtain a quick - dissolving, high - viscosity, environmentally friendly printing paste. The addition amount of the phosphorus - free chelating dispersant is 0.2% - 1% of the mass of the quick - dissolving, high - viscosity, environmentally friendly printing paste. It has strong chelating ability, can chelate a variety of metal ions, and can also play a role in accelerating dispersion and dissolution, obtaining a printing paste that dissolves quickly.

[0038] Example 1

[0039] The preparation method of the quick - dissolving, high - viscosity, environmentally friendly printing paste in this example includes the following steps:

[0040] (1) Add water to a continuously stirred and heatable container, and maintain the water temperature at 60 - 80°C; add dialdehyde starch and sodium alginate and dissolve them to obtain a mixed solution; add 95% ethanol to the mixed solution, and the volume ratio of the mixed solution to 95% ethanol is 1:1;

[0041] The dialdehyde content of the dialdehyde starch is 96%, the viscosity of the 6% solution is 10 cps, and the concentration is 2%;

[0042] The M / G ratio of sodium alginate is 1.5, the viscosity of the 1% solution is 800 cps, and the concentration is 1%;

[0043] (2) Add sulfuric acid to the mixed solution and adjust the pH of the solution to 1 - 1.5;

[0044] (3) React the above mixed solution, the reaction temperature is 80°C, and the reaction time is 10 h; under the action of a catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction to hydrophobically modify sodium alginate, obtaining a modified sodium alginate - starch paste;

[0045] (4) After the reaction, add a 10% concentration of NaOH solution to the sodium alginate - starch paste and adjust the pH to 6 - 7;

[0046] (5) Alcoholize the reaction product, filter, press, granulate, and dry to obtain a granular semi - finished product;

[0047] (6) Grind the granular semi - finished product and sieve it into 30 - mesh amorphous particles, and spray - mix and add a phosphorus - free chelating dispersant to obtain a quick - dissolving high - viscosity environmentally friendly printing paste; the dosage of the phosphorus - free chelating dispersant is 0.4%, and the phosphorus - free chelating dispersant mixed solution is a mixture of trisodium methylglycine diacetate (MGDA), tetrasodium glutamate diacetate (GLDA), and tetrasodium dicarboxymethyl aspartate (ASDA) in a ratio of 20:40:40.

[0048] Example 2

[0049] The preparation method of the quick - dissolving high - viscosity environmentally friendly printing paste in this example includes the following steps:

[0050] (1) Add water to a continuously stirred and heatable container, and maintain the water temperature at 60 - 80°C; add dialdehyde starch and sodium alginate and dissolve them to obtain a mixed solution; add 95% ethanol to the mixed solution, and the volume ratio of the mixed solution to 95% ethanol is 1:1;

[0051] The dialdehyde content of the dialdehyde starch is 97%, the viscosity of the 6% solution is 5 cps, and the concentration is 1.5%;

[0052] The M / G ratio of sodium alginate is 1.8, the viscosity of the 1% solution is 500 cps, and the concentration is 1.5%;

[0053] (2) Add sulfuric acid and hydrochloric acid with a volume ratio of 1:1 to the mixed solution, and adjust the pH of the solution to 1.5 - 2;

[0054] (3) React the above mixed solution at a reaction temperature of 70 °C for 12 h; under the action of a catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction to hydrophobically modify sodium alginate, obtaining a modified sodium alginate - starch paste;

[0055] (4) After the reaction, add a 10% concentration of NaOH solution to the sodium alginate - starch paste and adjust the pH to 7 - 8;

[0056] (5) Alcoholize the reaction product, filter, press, granulate, and dry to obtain a granular semi - finished product;

[0057] (6) Grind the granular semi - finished product and screen it into 40 - mesh irregular particles, and spray - mix and add a phosphorus - free chelating dispersant to obtain a quick - dissolving high - viscosity environmentally friendly printing paste; the dosage of the phosphorus - free chelating dispersant is 0.5%, and the phosphorus - free chelating dispersant mixed solution is a mixture of trisodium methylglycine diacetate (MGDA), tetrasodium glutamate diacetate (GLDA), tetrasodium dicarboxymethyl aspartate (ASDA), and tetrasodium iminodisuccinate (IDS) in a ratio of 30:20:20:30.

[0058] Example 3

[0059] The preparation method of the quick - dissolving high - viscosity environmentally friendly printing paste in this example includes the following steps:

[0060] (1) Add water to a continuously stirred and heat - able container, maintain the water temperature at 60 - 80 °C; add dialdehyde starch and sodium alginate to dissolve to obtain a mixed solution; add 95% ethanol to the mixed solution, and the volume ratio of the mixed solution to 95% ethanol is 1:1;

[0061] The dialdehyde content of the dialdehyde starch is 98%, the viscosity of the 6% solution is 6 cps, and the concentration is 2.5%;

[0062] The M / G ratio of sodium alginate is 2.1, the viscosity of the 1% solution is 400 cps, and the concentration is 2%;

[0063] (2) Add trifluoroacetic acid and boron trifluoride with a volume ratio of 2:1 to the mixed solution, and adjust the pH of the solution to 1 - 2;

[0064] (3) React the above mixed solution at a reaction temperature of 90 °C for 10 h; under the action of a catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction to hydrophobically modify sodium alginate, obtaining a modified sodium alginate - starch paste;

[0065] (4) After the reaction is completed, add a NaOH solution with a concentration of 10% to the sodium alginate-starch paste, and adjust the pH to 6.5 - 7.5;

[0066] (5) Alcoholize the reaction product, filter, press, granulate, and dry to obtain a granular semi-finished product;

[0067] (6) Grind the granular semi-finished product and screen it into 40-mesh irregular granules, and spray and mix with a phosphorus-free chelating dispersant to obtain a quick-dissolving high-viscosity environmentally friendly printing paste; the dosage of the phosphorus-free chelating dispersant is 0.6%, and the phosphorus-free chelating dispersant mixed solution is tetrasodium glutamate diacetate (GLDA), tetrasodium dicarboxymethyl aspartate (ASDA), and tetrasodium iminodisuccinate (IDS) mixed in a ratio of 30:40:30.

[0068] Comparative Example 1

[0069] The preparation method of the quick-dissolving high-viscosity environmentally friendly printing paste in Comparative Example 1 is basically the same as that in Example 1, except that the dialdehyde content of the dialdehyde starch is 90%.

[0070] Comparative Example 2

[0071] The preparation method of the quick-dissolving high-viscosity environmentally friendly printing paste in Comparative Example 2 is basically the same as that in Example 1, except that the M / G ratio of sodium alginate is 1.

[0072] Comparative Example 3

[0073] The preparation method of the quick-dissolving high-viscosity environmentally friendly printing paste in Comparative Example 3 is basically the same as that in Example 1, except that no phosphorus-free chelating dispersant is added in step (6).

[0074] Comparative Example 4

[0075] The quick-dissolving high-viscosity environmentally friendly printing paste in Comparative Example 4 only contains sodium alginate as a single component, and sodium alginate is directly used as the printing paste.

[0076] Perform performance tests on the printing pastes of Examples 1 - 3 and Comparative Examples 1 - 4, and the test results are shown in Table 1.

[0077] Table 1

[0078]

[0079] As can be seen from the results in Table 1, the novel printing thickeners obtained in Examples 1-3 have the advantages of high paste-forming rate, fast dissolution rate, etc., and have high printing color yield, rich and bright printing color; clear printing outline and obvious printing levels; good leveling property; easy to wash off, and the printed fabric has a good handfeel. Its comprehensive performance is superior to the printing thickener prepared by using sodium alginate alone.

[0080] The dialdehyde content of the dialdehyde starch used in Comparative Example 1 was 90%, and the purity was slightly low, resulting in a lower viscosity of the modified sodium alginate-starch thickener formed by the reaction than that of the printing thickener in the example, which affected the paste-forming rate of the product; in addition, due to the low purity of the dialdehyde starch, it could not undergo a sufficient acetalization reaction with sodium alginate, could not make sodium alginate undergo sufficient hydrophobic modification, and could not obtain a printing thickener with good hydrophobic modification effect, and the obtained printing thickener was prone to agglomeration.

[0081] The M / G ratio of the sodium alginate used in Comparative Example 2 was 1. There was less mannuronic acid and more guluronic acid in the sodium alginate, resulting in a relatively hard film formed on the fabric surface by the printed modified sodium alginate-starch thickener, and the printing uniformity and handfeel would decrease.

[0082] In Comparative Example 3, no phosphorus-free chelating dispersant was added, and the dissolution time of the obtained printing thickener would be prolonged, and the screen penetration, printing uniformity and handfeel would decrease.

[0083] In Comparative Example 4, sodium alginate alone was directly used as the printing thickener, and the comprehensive performance of Examples 1-3 was superior to that of the printing thickener prepared by using sodium alginate alone.

[0084] Certainly, the above description is not a limitation of the present invention, and the present invention is not 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 should also fall within the protection scope of the present invention.

Claims

1. A instant high-viscosity environmentally friendly printing paste, characterized in that, It comprises the following components: Modified sodium alginate-starch paste and a phosphorus-free chelating dispersant, wherein the preparation components of the modified sodium alginate-starch paste include dialdehyde starch and sodium alginate; The dialdehyde content of the dialdehyde starch is above 95%, and the M / G ratio of the sodium alginate is 1.5 - 2.5; The preparation method of the instant high-viscosity environment-friendly printing paste comprises the following steps: (1) Add water into a container, and maintain the water temperature at 60 - 80°C; add dialdehyde starch and sodium alginate and dissolve them to obtain a mixed solution; add 95% ethanol into the mixed solution; (2) Add a catalyst into the mixed solution, and adjust the pH of the solution to 1 - 2; (3) Under the action of the catalyst, sodium alginate and dialdehyde starch undergo an acetalization reaction to hydrophobically modify sodium alginate, thereby obtaining the modified sodium alginate-starch paste; (4) After the reaction ends, add a 10% concentration of NaOH solution into the sodium alginate-starch paste, and adjust the pH to 6 - 8; (5) Perform alcohol precipitation, filtration, pressing, granulation, and drying on the reaction product to obtain a granular semi-finished product; (6) Grind the granular semi-finished product and sieve it into irregular particles of 30 - 80 mesh, and spray and mix with a phosphorus-free chelating dispersant to obtain the instant high-viscosity environment-friendly printing paste.

2. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein The viscosity of an aqueous solution of dialdehyde starch with a mass concentration of 6% is 3 - 20 cps.

3. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein The viscosity of an aqueous solution of sodium alginate with a mass concentration of 1% is 400 - 800 cps.

4. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein The phosphorus-free chelating dispersant includes one or more of trisodium methylglycine diacetate, tetrasodium glutamate diacetate, tetrasodium dicarboxymethyl aspartate, and tetrasodium iminodisuccinate.

5. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein In step (1), the concentration of the dialdehyde starch is 1 - 3%, and the concentration of the sodium alginate is 1 - 2%.

6. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein In step (1), the volume ratio of the mixed solution to 95% ethanol is 1:

1.

7. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein In step (2), the catalyst includes one or more of sulfuric acid, hydrochloric acid, trifluoroacetic acid, and boron trifluoride.

8. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein In step (3), the reaction is carried out at a temperature of 70 - 90°C for 10 - 12 h.

9. The instant high-viscosity environment-friendly printing paste according to claim 1, wherein In step (6), the addition amount of the phosphorus-free chelating dispersant is 0.2% - 1% of the mass of the instant high-viscosity environment-friendly printing paste.

Images