Saturated water-based polyester and N-methylpiperidone composition and preparation method thereof

Abstract

The invention relates to the technical field of cotton polyester and dyeing agents, in particular to a saturated water-based polyester and N-methylpiperidone composition and a preparation method thereof.The preparation method comprises the following steps that S1, terephthalic acid, isophthalic acid-5-sodium sulfonate, ethylene glycol, polyethylene glycol and zinc acetate are put into a stainless steel reactor and stirred under nitrogen protection, and a mixture is obtained; carrying out full esterification reaction in a reactor at the temperature of 150-220 DEG C under the pressure of one atmospheric pressure to obtain an intermediate A and an intermediate B; s2, after esterification reaction is carried out for 1.5-2.5 hours, pressure relief is carried out, meanwhile, a polycondensation catalyst tetrabutyl titanate is added, and the temperature continues to rise to 240-270 DEG C under nitrogen protection; and S3, gradually vacuumizing and reducing pressure, and enabling the pressure in the kettle to be 0.1-0.3 Kpa and the vacuum time to be 2-3 hours, so as to obtain a saturated polyester resin product C with a macromolecular structure, thereby saving a reduction cleaning step, saving time, water and steam, and avoiding the application of a new product with risks of dangerous chemicals such as sodium hydrosulfite, caustic soda and the like.

Description

Technical Field

[0001] The present invention relates to the field of textile auxiliaries, and particularly to a preparation method of a composition of saturated aqueous polyester and N-methylpyrrolidone and the composition of this soaping agent. Background Art

[0002] The traditional dyeing process generally includes four steps: 1. Disperse dyes are used to dye polyester; 2. Reduction cleaning; 3. Reactive dyes are used to dye cotton; 4. Soaping. Among them, in the reduction cleaning process of step 2, 2 g / L of sodium hydroxide and 2 g / L of sodium hydrosulfite are commonly used, and they are kept warm for 20 min in an 85°C water bath environment to clean the unfixed disperse dyes on the surface of the polyester-cotton blended fabric, then washed with 70°C hot water and then with normal temperature water to remove the reduced disperse dyes and other impurities such as the reduction cleaning agent on the fabric surface, improve the color fastness of the fabric, and prepare for the next step of reactive dye over-dyeing cotton. After reactive dyes are used to dye cotton, soaping (commonly using 0.5 g / L of a soaping agent of the maleic acid-acrylic acid type, kept warm at 95°C for 20 min), hot water washing, cold water washing and other processes are required to remove the floating color on the fabric, improve the color fastness and color brightness, so as to meet the product requirements of customers. However, this process flow is long, energy-consuming and water-consuming, and the two cleaning processes increase the burden on subsequent sewage treatment; therefore, it is necessary to simplify the dyeing process flow of polyester-cotton blended fabrics, reduce the use of chemicals, and reduce the consumption of water resources. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method of a composition of saturated aqueous polyester and N-methylpyrrolidone and the composition of this soaping agent, which omits the reduction cleaning step, saves time, water and steam, and at the same time does not involve the risk of using dangerous chemicals such as sodium hydrosulfite and caustic soda.

[0004] The above technical purpose of the present invention is achieved through the following technical solutions: A composition of saturated aqueous polyester and N-methylpyrrolidone, the composition includes saturated aqueous polyester and N-methylpyrrolidone. Calculated by weight components, the saturated aqueous polyester includes the following raw materials: 80-110 parts of terephthalic acid, 100-140 parts of isophthalic acid-5-sulfonate, 55-75 parts of ethylene glycol, and 150-200 parts of polyethylene glycol.

[0005] Preferably, the molar ratio of terephthalic acid to isophthalic acid sulfonate is (0.5-0.6:0.4-0.5).

[0006] Preferably, calculated by weight components, the ratio of the saturated aqueous polyester to N-methylpyrrolidone is (20-30:3-5).

[0007] Preferably, the polyethylene glycol is one of polyethylene glycol PEG400, polyethylene glycol PEG800, or polyethylene glycol PEG1500.

[0008] Preferably, based on the weight fractions, the terephthalic acid is 107.9 parts, sodium isophthalate-5-sulfonate is 120.6 parts, ethylene glycol is 62 parts, and polyethylene glycol (PEG400) is 200 parts.

[0009] The present invention provides a method for preparing a composition of saturated aqueous polyester and N-methylpyrrolidone, comprising the following steps: Step S1, loading terephthalic acid, sodium isophthalate-5-sulfonate, ethylene glycol, polyethylene glycol and zinc acetate into a stainless steel reactor, stirring under nitrogen protection, and carrying out a sufficient esterification reaction at a temperature of 180°C and a pressure of one atmosphere in the reactor; Step S2, after 2 hours of esterification reaction, depressurize, and at the same time add tetrabutyl titanate as a polycondensation catalyst, and continue to heat up to 255°C under nitrogen protection; Step S3, gradually evacuate and reduce the pressure to make the pressure in the kettle 0.1 Kpa, and the vacuum time is 2-3 hours to obtain a saturated polyester resin product.

[0010] Preferably, in step S2, the pressure is released after 2 hours of esterification reaction.

[0011] Preferably, in step S2, continue to heat up to 250-260°C under nitrogen protection.

[0012] Preferably, in step S3, gradually evacuate and reduce the pressure to make the pressure in the kettle 0.1 Kpa.

[0013] By means of the above technical solutions, the present invention provides a remotely controllable magnetic component, which has at least the following beneficial effects: 1. In the present invention, the saturated aqueous polyester (35-45:55-65) of the present invention is a high molecular polymer with a special structure, which is similar to the molecular structure of polyester in the polyester-cotton fabric. However, because it has a hydrophilic sulfonate group, it has outstanding ability to strip the floating color of disperse dyes on polyester and the disperse dyes stained on cotton during the dyeing process of polyester-cotton. This is because the saturated aqueous high molecular compound is extremely similar to the structure of polyester fiber, and at high temperatures, it has strong ability to strip the unfixed floating color of disperse dyes. Also, since this high molecular compound is a strong anionic aqueous product, it can bring the unfixed disperse dyes into the water body, thereby achieving the purpose of removing the floating disperse dyes on polyester and the disperse dyes stained on cotton, and thus improving the soaping fastness of the polyester-cotton fabric.

[0014] 2. Currently, reactive dyes are mostly used in the cotton fabric dyeing process. Reactive dyes contain reactive groups with one or more functional groups, and there are a wide variety of them with diverse chemical structures. Therefore, the reaction efficiencies are also different. However, these different types of reactive dyes have one thing in common, that is, they cannot fully react with cellulose fibers during dyeing. In practical applications, they are combined with N-methylpyrrolidone. Because N-methylpyrrolidone belongs to azacyclic compounds, it is a non-protic solvent with strong polarity, low viscosity, strong dissolution ability, and chemical stability. There are reactive groups in the reactive dye molecules that can react with the hydroxyl groups in cellulose fibers to form covalent bonds, generating dye-fiber compounds. The un-fixed reactive dyes adhere to the fibers, and NMP has good solubility and removal ability for the un-fixed reactive dyes. Thus, the removal ability of the un-reacted and fixed reactive dyes on cotton can be achieved, and the soaping fastness of polyester-cotton fabrics can be significantly improved. Detailed implementation manners

[0015] The following are only the preferred implementation manners of the present invention, and the protection scope is not limited to this embodiment. All technical solutions within the idea of the present invention should belong to the protection scope of the present invention. At the same time, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

[0016] Load the corresponding amounts of terephthalic acid, isophthalic acid-5-sulfonate, ethylene glycol, polyethylene glycol, and 0.1 g of zinc acetate into a stainless steel reactor, stir under nitrogen protection, and carry out an esterification reaction at 150 - 220 °C. At the same time, esterify fully under a pressure of one atmosphere. After 2 hours of the esterification reaction, release the pressure, and at the same time add 0.05 g of tetrabutyl titanate as a polycondensation catalyst. Then continue to heat up under nitrogen protection, and slowly reduce the pressure to 250 - 260 °C. Keep the pressure in the kettle at about 0.1 Kpa under vacuum for about 2 - 3 hours, and obtain a saturated polyester resin with a saturated molecular structure under nitrogen protection and positive pressure. Then discharge the material to obtain 423.5 g of finished product. See the following table for details. Comparative Example 12, using the same ratio as in Example 1, and the difference from the preparation method of Example 1 is that: in step S2, continue to heat up to 240 °C under nitrogen protection.

[0017] Comparative Example 13, using the same ratio as in Example 1, and the difference from the preparation method of Example 1 is that: in step S2, continue to heat up to 280 °C under nitrogen protection.

[0018] Comparative Example 14, using the same ratio as in Example 1, and the difference from the preparation method of Example 1 is that: in step S3, gradually evacuate and reduce the pressure to make the pressure in the kettle 0.3 Kpa.

[0019] Performance characterization 1. Since some dyes will adhere to the fiber surface after dyeing, which affects the color fastness. To solve this problem, reduction cleaning is usually carried out after dyeing, aiming to remove the floating color and oligomers remaining on the fabric surface, thereby improving the color fastness and color shade. 100 g of a blended fabric with a polyester-cotton ratio of 1:1 was placed in a 1 L container, and the bath ratio was 1:20. 20 g of the finished products and corresponding compounding agents (N-methylpyrrolidone or N,N-dimethylformamide corresponding to the groups) of Examples 1 - 7 and Comparative Examples 1 to 11 were used for dyeing respectively, where the weight ratio of the finished product to the compounding agent was 25:4. In addition, experiments were carried out on Comparative Examples 12, 13, and 14 respectively, and then a reducing agent with a concentration of 2 g / L was used for floating color removal treatment, and the weight of the reducing agent used for floating color removal in each reduction reaction was compared.

[0020] Comparative Example 15 used the formulation of Example 2, and the difference from the preparation method of Example 2 was that the weight ratio of the finished product to the compounding agent was 15:4.

[0021] Comparative Example 16 used the formulation of Example 2, and the difference from the preparation method of Example 2 was that the weight ratio of the finished product to the compounding agent was 35:4.

[0022] Performance characterization 2. 100 g of a blended fabric with a polyester-cotton ratio of 1:1 was used, and the bath ratio was 1:20. 20 g of the finished products and corresponding compositions of Examples 1 - 7 and Comparative Examples 1 to 11 were used for dyeing respectively. After dyeing, it was washed with clean water, a softener was added to ensure that the fabric was fully stretched, and finally it was dried and shaped. The qualification rate was detected according to GB / T 3920 - 2024.

Claims

1. A saturated aqueous polyester and N-methylpyrrolidone composition, characterized in that, The composition comprises a saturated aqueous polyester and N-methylpyrrolidone. Based on the weight of the components, the saturated aqueous polyester comprises the following raw materials: 80-110 parts of terephthalic acid, 100-140 parts of isophthalic acid-5-sulfonate, 55-75 parts of ethylene glycol, and 150-200 parts of polyethylene glycol.

2. A saturated aqueous polyester and N-methylpyrrolidone composition according to claim 1, characterized in that The molar ratio of the terephthalic acid to the isophthalic acid sulfonate is (0.5-0.6:0.4-0.5).

3. The preparation method of a saturated aqueous polyester and N-methylpyrrolidone composition according to claim 1, characterized in that, Based on the weight of the components, the ratio of the saturated aqueous polyester to N-methylpyrrolidone is (20-30:3-5).

4. The preparation method of a saturated aqueous polyester and N-methylpyrrolidone composition according to claim 1, characterized in that, The polyethylene glycol is one of polyethylene glycol PEG400, polyethylene glycol PEG800, or polyethylene glycol PEG1500.

5. A method for preparing a composition of a saturated aqueous polyester and N-methylpyrrolidone according to claim 1, characterized in that, Based on the weight of the components, the terephthalic acid is 107.9 parts, the isophthalic acid-5-sulfonate is 120.6 parts, the ethylene glycol is 62 parts, and the polyethylene glycol (PEG400) is 200 parts.

6. The preparation method of a saturated aqueous polyester and N-methylpyrrolidone composition according to claim 1, characterized in that, It includes the following steps: Step S1, load terephthalic acid, isophthalic acid-5-sulfonate, ethylene glycol, polyethylene glycol, and zinc acetate into a stainless steel reactor, stir under nitrogen protection, and carry out a sufficient esterification reaction at a temperature of 150-220°C and a pressure of one atmosphere in the reactor; Step S2, after 1.5-2.5 hours of esterification reaction, relieve the pressure, and at the same time add tetrabutyl titanate as a polycondensation catalyst, and continue to heat up to 240-270°C under nitrogen protection; Step S3, gradually evacuate and reduce the pressure to make the pressure in the kettle 0.1-0.3 Kpa, and the vacuum time is 2-3 hours to obtain a saturated polyester resin product.

7. The preparation method of a saturated aqueous polyester and N-methylpyrrolidone composition according to claim 6, characterized in that, In Step S2, the pressure is relieved after 2 hours of esterification reaction.

8. The preparation method of a saturated aqueous polyester and N-methylpyrrolidone composition according to claim 6, characterized in that, In Step S2, continue to heat up to 250-260°C under nitrogen protection.

9. The preparation method of a saturated aqueous polyester and N-methylpyrrolidone composition according to claim 6, characterized in that, In Step S3, gradually evacuate and reduce the pressure to make the pressure in the kettle 0.1 Kpa.