Short-process printing process for cotton-polyester blended fabric

Abstract

The invention discloses a cotton-polyester blended fabric short-process printing process which comprises the following steps: carrying out screen printing by adopting active disperse dye containing double active groups, and steaming by alcohol-containing steam, wherein the double active groups comprise a hydroxyethyl sulfone sulfate group and CH2CH (OH) CH2X (X is Br or Cl); cH2CH (OH) CH2X can be converted into an epoxy group under an alkaline condition, and can react with alcohol-containing steam in a steaming process to realize cross-linking among dye molecules, so that the effects of improving the color fixing efficiency and shortening the technological process are achieved, and the printed fabric with high color depth and high color fastness is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of printing and dyeing, and in particular to a short-process printing process for a polyester-cotton blended fabric. Background Art

[0002] Polyester-cotton blended fabrics exhibit varying dyeing and printing properties due to the differing physical and chemical properties of polyester and cotton fibers. Therefore, selecting the appropriate printing method is crucial. Currently, printing methods for polyester-cotton blended fabrics are categorized into two main types: pigment printing and dye printing. Pigment printing involves bonding the pigment to the fabric surface using an adhesive, resulting in a poor print feel. Existing dye printing methods typically utilize disperse / reactive dyes or disperse / vat dyes for polyester-cotton blended fabrics. However, both methods require cumbersome post-processing, consume large amounts of water, and place significant pressure on wastewater treatment, necessitating further improvements.

[0003] One solution is to use reactive disperse dyes for printing. Reactive disperse dyes are based on disperse dyes, but the dye molecules contain reactive groups that can chemically bond with fibers. These dye molecules contain temporarily soluble anionic water-soluble groups, enabling them to dissolve in water and dye cotton fibers. Under specific conditions, they can then convert to nonionic properties and dye polyester like disperse dyes. While using reactive disperse dyes for polyester-cotton printing can shorten the process, issues such as insufficient dye uptake on polyester, cotton staining, and poor print clarity remain.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The invention provides a short-process printing process for polyester-cotton blended fabrics, aiming to reduce the printing process and time of polyester-cotton blended fabrics, improve the print clarity, apparent color depth and color fastness, and improve the cotton staining problem.

[0006] The present invention is achieved in that:

[0007] A short-process printing process for polyester-cotton blended fabrics, comprising the following steps:

[0008] (1) preparing a printing paste; the printing paste comprises the following components, calculated by mass percentage: 1% to 5% of active disperse dye, 1% to 5% of alkali agent, 0.8 to 1.2% of resist salt S, 3 to 7% of urea, 60% to 75% of paste, and the balance being water;

[0009] The reactive disperse dye has the following molecular structure:

[0010]

[0011] In the formula, R1 and R2 are independently selected from H or Br; Ar is R3 is H or CH3; R4 is H or NHCOCH3; R5 is CH2CH(OH)CH2Cl or CH2CH(OH)CH2Br; R6 is an alkyl group having 1 to 4 carbon atoms, C a H 2a CN、C b H 2b X, CH2CH(OH)CH2Cl or CH2CH(OH)CH2Br, a and b are independently any integer from 1 to 4, and X is Br or Cl;

[0012] (2) Printing by screen printing;

[0013] (3) baking;

[0014] (4) steaming with alcohol-containing steam;

[0015] (5) Washing with water;

[0016] (6) Drying.

[0017] The present invention uses reactive disperse dyes to print polyester-cotton blended fabrics, and adopts a screen printing method, combining pasting and printing into one step, thereby simplifying the process flow. Furthermore, the present invention uses alcohol-containing steam in combination with the reactive disperse dye of the present invention, thereby improving the color fixation efficiency, thereby simplifying the washing step, greatly simplifying the process flow, reducing water consumption and wastewater discharge. Specifically, the reactive disperse dye designed and developed by the present invention has two active groups, including hydroxyethyl sulfone sulfate and CH2CH(OH)CH2X (X is Br or Cl). The hydroxyethyl sulfone sulfate can be decomposed into ethyl sulfone under alkaline conditions, which can chemically bond with hydroxyl groups on cotton fibers, thereby fixing the color on the cotton fibers. The decomposed molecules have reduced water solubility, thereby increasing affinity for polyester fibers and facilitating diffusion into the interior of the polyester fibers. The CH2CH(OH)CH2X can remove HX under alkaline conditions and be converted into epoxy groups. The epoxy groups can be cross-linked by alcohol hydroxyl groups when steamed in alcohol-containing steam, thereby increasing the adhesion rate of the dye to the textile surface through cross-linking. Therefore, by using the reactive disperse dye provided by the present invention in combination with alcohol-containing steam for steaming, the printing process can be shortened, the dye-on-dye rate can be increased, thereby improving the printing efficiency, and improving the color depth and color fastness of the printed product.

[0018] In some embodiments, the paste comprises sodium alginate.

[0019] In some embodiments, the paste includes sodium alginate and gamma-polyglutamic acid.

[0020] Preferably, in the paste, the mass ratio of sodium alginate to γ-polyglutamic acid is (80:20) to (95:5).

[0021] γ-polyglutamic acid has good water-locking ability. Adding an appropriate amount can reduce the bleeding of printing paste and improve the clarity of printing. γ-polyglutamic acid also has excellent thixotropic properties, which can effectively improve the flow stability of the paste, thereby smoothly transferring it through the screen to the fabric. However, γ-polyglutamic acid should not be too much or too little. Too much can easily lead to too low viscosity of the printing paste and aggravate bleeding; too little can hardly play its modifying role.

[0022] In some embodiments, the percentage of water in the paste is 88% to 95%.

[0023] In some embodiments, the paste has a viscosity of 31,000 to 33,000 cps at 25° C. and normal pressure.

[0024] In some embodiments, the alcohol in the alcohol-containing steam in step (4) is selected from at least one of methanol, ethanol and propanol.

[0025] In some embodiments, the alcohol-containing vapor further contains triethylamine.

[0026] Further introducing triethylamine into the steam during steaming can increase the reactivity of alcohol and epoxy groups, improve the color fixing effect, and thus improve the color depth and color fastness of the print.

[0027] In some embodiments, the flow rate of alcohol in the alcohol-containing steam is 1 to 2 t / h.

[0028] In some embodiments, the flow rate of triethylamine in the alcohol-containing steam is 0.2-0.5 t / h.

[0029] In some embodiments, the alkaline agent is at least one of sodium bicarbonate, sodium carbonate, sodium hydroxide, and potassium hydroxide.

[0030] In some embodiments, the screen printing method includes rotary screen printing or flat screen printing.

[0031] In some embodiments, the baking temperature is 150-250° C., and the baking time is 8-15 minutes.

[0032] In some embodiments, the steaming temperature is 90-110° C., and the steaming time is 5-15 minutes.

[0033] In some embodiments, the water washing temperature is 60° C., and the bath ratio is 1:(20-30).

[0034] In some embodiments, the method for preparing the reactive disperse dye comprises the following steps:

[0035] S1, preparation of a diazo component: subjecting a para-ester or a derivative thereof to a diazotization reaction in the presence of hydrochloric acid and sodium nitrite to obtain a diazo component;

[0036] S2, preparation of coupling component: reacting aniline or its derivative with haloepoxypropane in the presence of a catalyst with stirring, and obtaining coupling component after first purification;

[0037] S3, preparation of reactive disperse dyes: dissolving the coupling component in an acid solution, then adding the diazo component to carry out a coupling reaction, and obtaining the reactive disperse dyes after a second purification.

[0038] In some embodiments, the para-ester or its derivative in step S1 includes a para-ester or a bromo-para-ester.

[0039] In some embodiments, the molar ratio of the para-ester or its derivative, sodium nitrite, and hydrogen chloride in hydrochloric acid is 1:1.05-1.3:2-4.

[0040] In some embodiments, the diazotization reaction is carried out at a temperature of 0 to 5° C. and for a time of 1 to 2 hours.

[0041] In some embodiments, the aniline or its derivative in step S2 includes at least one of aniline, N-alkylaniline, N-phenylcyanamide, anilinoacetonitrile, 3-(phenylamino)propionitrile, 4-(phenylamino)butyronitrile, chloromethylaniline, N-(3-chloropropyl)aniline, o-benzylamine, m-aminoacetanilide, N-(3-amino-4-methylphenyl)acetamide, N-methyl-o-methylaniline, N-ethyl-2-methylaniline, N-[3-(methylamino)phenyl]acetamide, 3-N-ethylaminoacetanilide, N1-[3-(ethylamino)-4-methylphenyl]acetamide, N-{3-[(cyanomethyl)amino]phenyl}acetamide, N-(o-tolyl)cyanamide, N-methyl-1-naphthylamine and N1-[3-(ethylamino)-4-methylphenyl]acetamide.

[0042] In some embodiments, the haloepoxypropane is epichlorohydrin or epibromohydrin.

[0043] In some embodiments, the molar ratio of the aniline or its derivative to the haloepoxypropane is 1:5-15.

[0044] In some embodiments, the catalyst is an organic ammonium salt, preferably tetrabutylammonium bromide or benzyltriethylammonium chloride.

[0045] In some embodiments, the catalyst is added in an amount of 2% by weight of aniline or its derivatives.

[0046] In some embodiments, the stirring reaction temperature is 30 to 50° C., and the stirring reaction time is 24 to 36 hours.

[0047] In some embodiments, the first purification refers to distillation under reduced pressure at 120°C.

[0048] In some embodiments, the acid solution in step S3 is an aqueous solution containing 10% to 30% hydrogen chloride or acetic acid.

[0049] In some embodiments, the molar ratio of the diazo component to the coupling component is 1:1.

[0050] In some embodiments, the second purification comprises filtering the reaction solution at 5-10° C., then washing the filter cake with a saturated sodium chloride aqueous solution at 0-5° C. and water in sequence, and finally drying.

[0051] The present invention has the following beneficial effects:

[0052] The present invention provides a short-process printing process for polyester-cotton blended fabrics. This process utilizes reactive disperse dyes to achieve simultaneous printing of polyester and cotton, and employs a specific steaming process to enhance dye fixation on the polyester. This shortens the washing and color fixation process, reduces cotton staining, and improves the fabric's color depth and color fastness. Furthermore, the paste employed in the present invention contains γ-polyglutamic acid, which, due to its excellent water retention and thixotropic properties, enhances the fabric's water absorption and the paste's flow stability, thereby reducing pattern edge burrs caused by bleed-through and enhancing print clarity. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 The infrared spectra of dye 1 and dye 2 prepared in Example 1 and Example 3 are shown;

[0055] Figure 2 These are infrared spectra of dye 3 and dye 4 prepared in Example 4 and Example 5. DETAILED DESCRIPTION

[0056] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0057] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0058] Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0059] In the embodiment of the present application, the term "or / and" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A or / and B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0060] In addition, the character “ / ” in this article generally indicates that the previous and next related objects are in an “or” relationship.

[0061] In the embodiments of the present application, "multiple" means more than two (including two). Similarly, "multiple groups" means more than two groups (including two groups), and "multi-layer" means more than two layers (including two layers), unless otherwise clearly specified and limited.

[0062] In the embodiments of the present application, “at least one” means one or more than one.

[0063] Those skilled in the art may understand the specific meanings of the above terms in the embodiments of this application based on specific circumstances.

[0064] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0065] Example 1

[0066] A short-process printing process for polyester-cotton blended fabrics, comprising the following steps:

[0067] (1) Preparation of printing paste

[0068] The printing paste formula, calculated by mass percentage, includes the following components: 3% active disperse dye (dye 1), 2.8% sodium bicarbonate, 1% resist salt S, 5% urea, 70% sodium alginate paste, and the balance is water.

[0069] The sodium alginate paste has a sodium alginate content of 8% by mass and is prepared as follows: sodium alginate powder is added to water, homogenized for 2 hours, then allowed to stand for expansion, and finally water is added to the mixture and stirred until uniform. The viscosity at 25° C. is 32000±1000 cps.

[0070] The reactive disperse dye has the following molecular structure, which is recorded as dye 1:

[0071]

[0072] The maximum absorption wavelength of the dye was measured using a Hitachi U-3310 UV spectrophotometer, and the melting point of the dye was measured using an MP90 melting point instrument. Dye 1 has a maximum absorption wavelength of 461 nm, a yellow color, and a melting point of 136°C.

[0073] (2) Rotary screen printing is performed. The printed patterns include linear and block patterns. A Japanese Dongshen magnetic rod rotary screen printing machine is used. The mesh number of the rotary screen is 105 meshes. A No. 15 magnetic rod is used. The speed is 20 m / min. The specifications of the polyester-cotton blended fabric are 21s×21s and 108×58.

[0074] (3) Baking: Baking at 150°C for 10 min;

[0075] (4) Alcohol steaming: temperature 100°C, time 8 min; steam composition includes ethanol and triethylamine, alcohol flow rate is 1.5 t / h, triethylamine flow rate is 0.4 t / h;

[0076] (5) Water washing: water temperature is 60℃, bath ratio is 1:20.

[0077] (6) Drying.

[0078] The preparation method of reactive disperse dyes comprises the following steps:

[0079] (1) Preparation of diazo component: The para-ester is dispersed in water, cooled to 0-5°C, and then concentrated hydrochloric acid is added. The mixture is stirred at this temperature for 20 minutes. A 30 wt% aqueous sodium nitrite solution is added dropwise over 30 minutes. The mixture is stirred at this temperature for 1 hour to carry out diazotization reaction. Finally, sulfamic acid is added and stirred for 20 minutes to eliminate excess nitrous acid to obtain the diazo component. The molar ratio of the para-ester, sodium nitrite, and hydrogen chloride in the hydrochloric acid is 1:1.1:3.

[0080] (2) Preparation of coupling component: N-butylaniline, epichlorohydrin, and catalyst tetrabutylammonium bromide were mixed, stirred until completely clear, reacted at 40°C with stirring for 36 hours, and then distilled under reduced pressure at 120°C to obtain a viscous coupling component; wherein the molar ratio of N-butylaniline to epichlorohydrin was 1:10; the amount of tetrabutylammonium bromide added was 2% of the mass of N-butylaniline;

[0081] (3) Preparation of reactive disperse dyes: The coupling component was dissolved in a 10 wt% hydrochloric acid solution, cooled to 0-5°C, and the diazo component was added dropwise over 30 min. Then, sodium bicarbonate was added to adjust the pH to 3. The mixture was stirred at 20°C for 3 h to carry out a coupling reaction. The end point of the reaction was tested with a 0.5% H2O solution. The reaction solution was cooled to 5-10°C, filtered while cold, and the filter cake was washed with a 0-5°C saturated sodium chloride aqueous solution and water in sequence. The filter cake was dried at 60°C to obtain a reactive disperse dye (dye 1). The mass ratio of the coupling component to the 10 wt% hydrochloric acid solution was 1:1, and the molar ratio of the coupling component to the molar ratio of the diazo component was 1:1.

[0082] Through the above preparation method, the yield of dye 1 (calculated as para-ester) is 95.4%.

[0083] The infrared spectrum of dye 1 (tested by KBr tablet method) is shown in the attached figure. Figure 1 As shown, at 1600cm -1 , 1500cm -1 、1450cm -1 The absorption peak near the benzene ring is the skeleton vibration peak at 830cm -1 The absorption peaks near the disubstituted aromatic ring correspond to the bending vibration peaks of CH at 2850-2950 cm -1 The two absorption peaks correspond to the symmetrical and antisymmetrical stretching vibration peaks of alkyl CH; at 3600-3200 cm -1 The strong absorption peak corresponds to the stretching vibration peak of hydroxyl; at 1350-1260cm -1 The absorption peak corresponds to the in-plane bending vibration peak of the secondary alcohol OH, at 1100 cm -1 The absorption peak near 1330cm is the CO stretching vibration peak of secondary alcohol; -1 and 1140cm -1 The two absorption peaks nearby correspond to the symmetric and antisymmetric stretching vibration absorption peaks of -S02-.

[0084] Example 2

[0085] The difference from Example 1 is that a composite paste is used instead of sodium alginate paste. In the composite paste, the mass percentage content of γ-polyglutamic acid is 0.8%, and the mass percentage content of sodium alginate is 7.2%. The preparation method is as follows: sodium alginate powder and γ-polyglutamic acid powder are added to water, homogenized for 2 hours, then allowed to stand for expansion, and finally water is added to the volume and stirred until uniform. The viscosity at 25°C is 32000±1000cps.

[0086] Example 3

[0087] The difference from Example 2 is that dye 2 is used instead of dye 1 as the reactive disperse dye to prepare the printing paste. The molecular structure of dye 2 is as follows:

[0088]

[0089] The maximum absorption wavelength of dye 2 is 458 nm, it is yellow, and its melting point is 132°C.

[0090] The preparation method of dye 2 comprises the following steps:

[0091] (1) Same as Example 1;

[0092] (2) Preparation of coupling component: Aniline, epichlorohydrin, and tetrabutylammonium bromide catalyst were mixed, stirred until completely clear, stirred and reacted at 40°C for 36 hours, and then distilled under reduced pressure at 120°C to obtain a viscous coupling component; wherein the molar ratio of aniline to epichlorohydrin was 1:15; the amount of tetrabutylammonium bromide added was 2% of the mass of aniline;

[0093] (3) Same as Example 1.

[0094] Through the above preparation method, the yield of dye 2 (calculated as para-ester) is 96.6%.

[0095] The infrared spectrum of dye 2 (tested by KBr tablet method) is shown in the attached figure. Figure 1 As shown, compared with dye 1, the -1 The absorption peak intensity increases greatly, indicating that the content of alcohol hydroxyl groups increases.

[0096] Example 4

[0097] A short-process printing process for polyester-cotton blended fabrics, comprising the following steps:

[0098] (1) Preparation of printing paste

[0099] The printing paste formula, calculated by mass percentage, includes the following components: 1% active disperse dye (dye 3), 1.2% sodium bicarbonate, 0.8% resist salt S, 3% urea, 75% composite paste, and the balance is water.

[0100] The composite paste contains 0.8% by weight of γ-polyglutamic acid and 7.2% by weight of sodium alginate. The preparation method is as follows: Sodium alginate powder and γ-polyglutamic acid powder are added to water and homogenized for 2 hours. The mixture is then allowed to swell. Finally, water is added to the mixture and stirred until uniform. The viscosity at 25°C is 32,000 ± 1,000 cps.

[0101] The reactive disperse dye has the following molecular structure, which is recorded as dye 3:

[0102]

[0103] The maximum absorption wavelength of dye 3 is 548 nm, it is red, and its melting point is 181°C.

[0104] (2) Rotary screen printing was performed as in Example 1;

[0105] (3) Baking: Baking at 210°C for 8 min;

[0106] (4) Alcohol steaming: temperature 90°C, time 5 min; steam composition includes ethanol and triethylamine, alcohol flow rate is 1 t / h, triethylamine flow rate is 0.2 t / h;

[0107] (5) Water washing: same as in Example 1.

[0108] (6) Drying.

[0109] The preparation method of reactive disperse dyes comprises the following steps:

[0110] (1) Preparation of diazo component: The bromo-para-ester is dispersed in water, cooled to 0-5°C, and then concentrated hydrochloric acid is added. The mixture is stirred at this temperature for 20 minutes. A 30 wt% aqueous sodium nitrite solution is added dropwise over 30 minutes. The mixture is stirred at this temperature for 1 hour to carry out diazotization reaction. Finally, sulfamic acid is added and stirred for 20 minutes to eliminate excess nitrous acid to obtain the diazo component. The molar ratio of the bromo-para-ester, sodium nitrite, and hydrogen chloride in the hydrochloric acid is 1:1.1:3.

[0111] (2) Preparation of coupling component: N1-[3-(ethylamino)-4-methylphenyl]acetamide, epichlorohydrin, and catalyst tetrabutylammonium bromide were mixed, stirred until completely clear, reacted at 50°C with stirring for 36 hours, and then distilled under reduced pressure at 120°C to obtain a viscous coupling component; wherein the molar ratio of N1-[3-(ethylamino)-4-methylphenyl]acetamide to epichlorohydrin was 1:15; and the amount of tetrabutylammonium bromide added was 2% of the mass of N1-[3-(ethylamino)-4-methylphenyl]acetamide;

[0112] (3) Preparation of reactive disperse dyes: The coupling component was dissolved in a 30 wt% aqueous acetic acid solution, cooled to 0-5°C, and the diazo component was added dropwise over 30 min. Then, sodium bicarbonate was added to adjust the pH to 4. The mixture was stirred at 20°C for 3 h to carry out a coupling reaction. The end point of the reaction was tested with a 0.5% H2O solution. The reaction solution was cooled to 5-10°C, filtered while cold, and the filter cake was washed with a 0-5°C saturated sodium chloride aqueous solution and water in sequence. The filter cake was dried at 60°C to obtain a reactive disperse dye (dye 3). The mass ratio of the coupling component to the 30 wt% aqueous acetic acid solution was 1:1, and the molar ratio of the coupling component to the molar ratio of the diazo component was 1:1.

[0113] The yield of dye 3 (based on the brominated para-ester) was 93.8% by the above preparation method. The infrared spectrum of dye 3 is shown in the attached figure. Figure 2 shown.

[0114] Example 5

[0115] A short-process printing process for polyester-cotton blended fabrics, comprising the following steps:

[0116] (1) Preparation of printing paste

[0117] The printing paste formula, calculated by mass percentage, includes the following components: 5% active disperse dye (dye 3), 4.3% sodium bicarbonate, 1.2% resist salt S, 7% urea, 60% composite paste, and the balance is water.

[0118] The composite paste contains 0.8% by weight of γ-polyglutamic acid and 7.2% by weight of sodium alginate. The preparation method is as follows: Sodium alginate powder and γ-polyglutamic acid powder are added to water and homogenized for 2 hours. The mixture is then allowed to swell. Finally, water is added to the mixture and stirred until uniform. The viscosity at 25°C is 32,000 ± 1,000 cps.

[0119] The reactive disperse dye has the following molecular structure, which is recorded as dye 4:

[0120]

[0121] The maximum absorption wavelength of dye 3 is 495 nm, its color is orange, and its melting point is 154°C.

[0122] (2) Flat screen printing, using a Japanese Dongshen flatbed printing machine;

[0123] (3) Baking: Baking at 170°C for 15 min;

[0124] (4) Alcohol steaming: temperature 110°C, time 15 min; steam composition includes ethanol and triethylamine, alcohol flow rate is 2 t / h, triethylamine flow rate is 0.5 t / h;

[0125] (5) Washing: Same as Example 1.

[0126] (6) Drying.

[0127] The preparation method of reactive disperse dye (dye 4) comprises the following steps:

[0128] (1) Preparation of diazo component: same as Example 4;

[0129] (2) Preparation of coupling component: N-{3-[(cyanomethyl)amino]phenyl}acetamide, epichlorohydrin, and catalyst tetrabutylammonium bromide were mixed, stirred until completely clear, reacted at 50°C with stirring for 36 hours, and then distilled under reduced pressure at 120°C to obtain a viscous coupling component; wherein the molar ratio of N-{3-[(cyanomethyl)amino]phenyl}acetamide to epichlorohydrin was 1:15; and the amount of tetrabutylammonium bromide added was 2% of the mass of N-{3-[(cyanomethyl)amino]phenyl}acetamide;

[0130] (3) Preparation of reactive disperse dyes: same as in Example 4.

[0131] The yield of dye 4 (based on the brominated para-ester) is 956% by the above preparation method. The infrared spectrum of dye 4 is shown in the attached figure. Figure 2 shown.

[0132] Example 5

[0133] The difference from Example 2 is that Dye 5 is used instead of Dye 1 as the reactive disperse dye, and the baking temperature is 170° C. and the baking time is 15 min. The molecular structure of Dye 5 is as follows:

[0134]

[0135] The dye 5 absorbs light at a wavelength of 512nm, is orange-red, and has a melting point of 162°C.

[0136] The preparation method of dye 5 comprises the following steps:

[0137] (1) Same as Example 1;

[0138] (2) Preparation of coupling component: N-methyl-1-naphthylamine, epichlorohydrin, and benzyltriethylammonium chloride catalyst were mixed, stirred until completely clear, stirred at 40°C for 36 hours, and then distilled under reduced pressure at 120°C to obtain a viscous coupling component; wherein the molar ratio of N-methyl-1-naphthylamine to epichlorohydrin was 1:5; and the amount of benzyltriethylammonium chloride added was 2% of the mass of N-methyl-1-naphthylamine;

[0139] (3) Same as Example 1.

[0140] Through the above preparation method, the yield of dye 5 (calculated as para-ester) is 95.7%.

[0141] Example 7

[0142] The difference from Example 2 is that in the composite paste, the mass percentage content of γ-polyglutamic acid is 0.4%, and the mass percentage content of sodium alginate is 7.6%. The preparation method is as follows: sodium alginate powder and γ-polyglutamic acid powder are added to water, homogenized for 2 hours, then allowed to stand for expansion, and finally water is added to the volume and stirred until uniform. The viscosity at 25°C is 32000±1000cps.

[0143] Example 8

[0144] The difference from Example 2 is that in the composite paste, the mass percentage content of γ-polyglutamic acid is 1.6%, and the mass percentage content of sodium alginate is 6.4%. The preparation method is as follows: sodium alginate powder and γ-polyglutamic acid powder are added to water, homogenized for 2 hours, then allowed to stand for expansion, and finally water is added to the volume and stirred until uniform. The viscosity at 25°C is 32000±1000cps.

[0145] Example 9

[0146] The difference from Example 2 is that triethylamine is not introduced during alcohol distillation.

[0147] Comparative Example 1

[0148] The difference from Example 3 is that dye 6 is used instead of dye 1 as the dye. The molecular structure of dye 6 is as follows:

[0149]

[0150] The maximum absorption wavelength of dye 6 is 118 nm, it is yellow, and its melting point is 117°C.

[0151] The preparation method of dye 6 comprises the following steps:

[0152] (1) Preparation of the diazo component: Aniline was dispersed in water, cooled to 0-5°C, and then concentrated hydrochloric acid was added. The mixture was stirred at this temperature for 20 minutes. A 30 wt% aqueous sodium nitrite solution was added dropwise over 30 minutes. The mixture was stirred at this temperature for 1 hour to carry out a diazotization reaction. Finally, sulfamic acid was added and stirred for 20 minutes to eliminate excess nitrous acid to obtain the diazo component. The molar ratio of aniline, sodium nitrite, and hydrogen chloride in the hydrochloric acid was 1:1.1:3.

[0153] (2) Same as Example 3;

[0154] (3) Same as Example 3.

[0155] Through the above preparation method, the yield of dye 6 (calculated as aniline) is 98.3%.

[0156] Comparative Example 2

[0157] The difference from Example 3 is that it includes the following two items:

[0158] (1) The printing paste formula includes the following components, calculated by mass percentage: 3% active disperse dye (dye 2 in Example 3), 2.8% sodium bicarbonate, 1% resist salt S, 5% urea, 2% ethylene glycol, 68% composite paste (same as in Example 3), and the balance is water.

[0159] (2) Conventional steaming was used instead of alcohol steaming to steam the printed fabric. The specific steaming steps were as follows: temperature 102°C, time 10 min, and steam flow rate 1.5 t / h.

[0160] Comparative Example 3

[0161] The difference from Example 3 is that it includes the following two items:

[0162] (1) The printing paste formula includes the following components, calculated by mass percentage: 3% active disperse dye (dye 6 in Comparative Example 1), 2.8% sodium bicarbonate, 1% resist salt S, 5% urea, 2% ethylene glycol, 68% composite paste (same as in Example 3), and the balance is water.

[0163] (2) Conventional steaming was used instead of alcohol steaming to steam the printed fabric. The specific steaming steps were as follows: temperature 102°C, time 10 min, and steam flow rate 1.5 t / h.

[0164] Test Example 1 De-paste Rate

[0165] The quality of the polyester-cotton blended fabric was tested before printing, after printing (including printing and drying), and after post-treatment (including baking, steaming, washing, and drying), corresponding to m1, m2, and m3. Each test was conducted after the corresponding process was completed and the fabric was left to stand at standard temperature and humidity for 24 hours. The de-pasting rate was calculated as (m2-m3) / (m2--m1)×100%. The results are listed in Table 1.

[0166] Test Example 2 Printing Clarity

[0167] Two sets of straight lines were printed on a polyester-cotton blended fabric. Each set consisted of three identical lines arranged in parallel. One set consisted of thin lines measuring 10 cm x 100 μm in length x width; the other set consisted of thick lines measuring 10 cm x 1000 μm in length x width. The fineness of the lines was measured under a microscope. The line width was measured at intervals of 1 cm along each line, for a total of 30 points per set. The average width and coefficient of variation (coefficient of variation = sample standard deviation / mean) of each line set were calculated. The results are listed in Table 1.

[0168] Table 1

[0169]

[0170] The de-pasting rate refers to the ease with which the paste can be removed from the fabric during the post-printing process. The de-pasting rate directly affects the printing effect and the feel of the fabric. If the de-pasting rate is too low, the paste will be difficult to remove from the fabric, resulting in unclear printing and even affecting the air permeability and comfort of the fabric. Therefore, it is crucial to control the de-pasting rate of the paste. The present invention uses the average width and coefficient of variation of the lines to evaluate the clarity of the printed pattern. The more the average width deviates from 100 μm and / or 1000 μm, the greater the degree of penetration of the color paste; the larger the coefficient of variation, the greater the degree of discreteness of the numerical value, that is, the worse the clarity of the pattern outline. In Example 1 and Example 2 of the present invention, sodium alginate paste and a composite paste containing γ-polyglutamic acid are used respectively. The de-pasting rate and print clarity of the two are significantly different. Since γ-polyglutamic acid is added to the paste of Example 2, it has a higher de-pasting rate and print clarity. The reason is that γ-polyglutamic acid has a higher water-locking ability and reduces the penetration of the color paste. In addition, the addition of γ-polyglutamic acid can effectively improve the thixotropic properties of the paste, so that it has better thixotropy under the action of shear force, thereby transferring to the fabric through the screen. The composite pastes of Examples 2, 7, and 8 contain different proportions of γ-polyglutamic acid. From the results, it can be seen that as the content of γ-polyglutamic acid increases, the de-pasting rate is higher, but the print clarity first increases and then decreases; the reason is that γ-polyglutamic acid is more hydrophilic, making it easier to remove; although the water absorption rate of γ-polyglutamic acid is higher than that of sodium alginate, it does not have a rigid sugar ring structure, which makes its viscosity lower than that of sodium alginate. Therefore, if the content is too high, the viscosity of the color paste decreases too much, which aggravates the penetration. The dye 2 used in Example 3 can generate two epoxy groups under the action of alkali and heat, causing excessive cross-linking during baking and alcohol steaming, and even bonding with the paste, thereby reducing the de-pasting rate.

[0171] Test Example 3: Apparent Color Depth

[0172] The apparent color depth K / S value of printed fabrics was tested using a Datacolor 650 tester.

[0173] Test Example 4 Color Fastness

[0174] The color fastness of dyed fabrics to washing with soap and soap is tested in accordance with GB / T 3921-2008 "Textiles — Tests for color fastness — Color fastness to washing with soap and soap". The color fastness of dyed fabrics to rubbing is tested in accordance with GB / T 3920-2008 "Textiles — Tests for color fastness — Color fastness to rubbing". The color fastness of dyes to sunlight is tested in accordance with GB / T 8427-2008 "Textiles — Tests for color fastness to artificial light: Xenon arc fading lamp".

[0175] Table 2

[0176]

[0177]

[0178] As can be seen from the results in the table, the prints obtained by the method provided by the present invention have good color depth K / S value and color fastness. Compared with Example 3, the dye in Comparative Example 1 does not contain hydroxyethyl sulfone sulfate group, which reduces its reactivity with cotton fiber, so the dye uptake is low, so the K / S value decreases; but because the dye is attached to the fabric surface by chemical bonding or cross-linking, the color fastness is higher. Comparative Example 2 does not use alcohol distillation, but adds alcohol substances to the paste and adopts conventional steam distillation. The K / S value of the print is not as good as that of Example 3. The reason is that the alcohol substance contacts the paste in a vaporized manner, which increases the contact degree and reactivity of the two, thereby facilitating the polymerization reaction. The dye in Comparative Example 3 does not contain hydroxyethyl sulfone sulfate group and is not alcohol distilled, so the K / S value is the worst.

[0179] The addition of polyglutamic acid to the paste of Example 2 makes the apparent color depth of the printing larger relative to Example 1. The reason is that v-polyglutamic acid improves the thixotropy of the paste and the affinity with polyester fiber, making it better attached to the blended fabric surface through the screen, but because the dyes of the two are the same, the difference in color fastness is not much. The cross-linking groups of Example 3 are more than those of Example 1, but the color fastness of the printing is not significantly improved. Instead, the K / S value of the printing is decreased. The possible reason is that -CH2CHOHCH2Cl is replaced by alkyl butyl, which improves the molar absorption coefficient of the dye. The dye 3 used in Example 4 is red. Although the content of the dye in the paste is lower, a higher K / S value is still obtained. The dye 4 used in Example 5 is orange. Since the content of the dye in the paste is higher, the K / S value is also higher. The paste of Example 7 had a low γ-polyglutamic acid content, while the paste of Example 8 had a high γ-polyglutamic acid content, resulting in lower K / S values ​​than Example 2. This is because excessively high γ-polyglutamic acid content exacerbates color paste penetration, while low γ-polyglutamic acid content reduces color paste transmittance, both of which hinder the color paste from remaining on the fabric surface. In Example 9, triethylamine was not added during the alcohol distillation process. Triethylamine, as a reaction catalyst, reduces the reactivity of epoxy groups with alcohol, resulting in lower K / S values ​​and color fastness.

[0180] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A short-process printing process for polyester-cotton blended fabrics, characterized in that: The following steps are involved: (1) preparing a printing paste; the printing paste comprises the following components, calculated by mass percentage: 1% to 5% of active disperse dye, 1% to 5% of alkali agent, 0.8 to 1.2% of resist salt S, 3 to 7% of urea, 60% to 75% of paste, and the balance being water; The reactive disperse dye has the following molecular structure: In the formula, R1 and R2 are independently selected from H or Br; Ar is R3 is H or CH3; R4 is H or NHCOCH3; R5 is CH2CH(OH)CH2Cl or CH2CH(OH)CH2Br; R6 is an alkyl group having 1 to 4 carbon atoms, C a H 2a CN、C b H 2b X, CH2CH(OH)CH2Cl or CH2CH(OH)CH2Br, a and b are independently any integer from 1 to 4, and X is Br or Cl; (2) Printing by screen printing; (3) baking; (4) steaming with alcohol-containing steam; (5) Washing with water; (6) Drying.

2. The short-process printing process for polyester-cotton blended fabric according to claim 1, characterized in that: The paste comprises sodium alginate; Preferably, the paste comprises sodium alginate and γ-polyglutamic acid; Preferably, in the paste, the mass ratio of sodium alginate to γ-polyglutamic acid is (80:20) to (95:5); Preferably, the percentage of water in the paste is 88% to 95%.

3. The short-process printing process for polyester-cotton blended fabric according to claim 1 or 2, characterized in that: The viscosity of the paste at 25° C. and normal pressure is 31,000 to 33,000 cps.

4. The short-process printing process for polyester-cotton blended fabric according to any one of claims 1 to 3, characterized in that: In the alcohol-containing steam of step (4), the alcohol is selected from at least one of methanol, ethanol and propanol; Preferably, the alcohol-containing steam further contains triethylamine; Preferably, the flow rate of alcohol in the alcohol-containing steam is 1 to 2 t / h; Preferably, the flow rate of triethylamine in the alcohol-containing steam is 0.2-0.5 t / h.

5. The short-process printing process for polyester-cotton blended fabric according to any one of claims 1 to 4, characterized in that: The alkaline agent is at least one of sodium bicarbonate, sodium carbonate, sodium hydroxide and potassium hydroxide; And / or, the screen printing method includes rotary screen printing or flat screen printing; And / or, the baking temperature is 150-250° C., and the baking time is 8-15 min; And / or, the steaming temperature is 90-110° C., and the steaming time is 5-15 min; And / or, the water washing temperature is 60° C., and the bath ratio is 1:(20-30).

6. The short-process printing process for polyester-cotton blended fabric according to any one of claims 1 to 5, characterized in that: The preparation method of the reactive disperse dye comprises the following steps: S1, preparation of a diazo component: subjecting a para-ester or a derivative thereof to a diazotization reaction in the presence of hydrochloric acid and sodium nitrite to obtain a diazo component; S2, preparation of coupling component: reacting aniline or its derivative with haloepoxypropane in the presence of a catalyst with stirring, and obtaining coupling component after first purification; S3, preparation of reactive disperse dyes: dissolving the coupling component in an acid solution, then adding the diazo component to carry out a coupling reaction, and obtaining the reactive disperse dyes after a second purification.

7. The short-process printing process for polyester-cotton blended fabric according to claim 6, characterized in that: The para-ester or its derivative in step S1 includes a para-ester or a brominated para-ester; and / or, the molar ratio of the para-ester or its derivative, sodium nitrite, and hydrogen chloride in hydrochloric acid is 1:1.05-1.3:2-4; And / or, the temperature of the diazotization reaction is 0-5°C and the time is 1-2 hours.

8. The short-process printing process for polyester-cotton blended fabric according to claim 6, characterized in that: The aniline or derivatives thereof in step S2 include at least one of aniline, N-alkylaniline, N-phenylcyanamide, anilinoacetonitrile, 3-(phenylamino)propionitrile, 4-(phenylamino)butyronitrile, chloromethylaniline, N-(3-chloropropyl)aniline, o-benzylamine, m-aminoacetanilide, N-(3-amino-4-methylbenzene)acetamide, N-methyl-o-methylaniline, N-ethyl-2-methylaniline, N-[3-(methylamino)phenyl]acetamide, 3-N-ethylaminoacetanilide, N1-[3-(ethylamino)-4-methylphenyl]acetamide, N-{3-[(cyanomethyl)amino]phenyl}acetamide, N-(o-tolyl)cyanamide, N-methyl-1-naphthylamine and N1-[3-(ethylamino)-4-methylphenyl]acetamide; And / or, the halogenated epoxypropane is epichlorohydrin or epibromohydrin; and / or, the molar ratio of the aniline or its derivative to the haloepoxypropane is 1:5-15; and / or, the catalyst is an organic ammonium salt, preferably tetrabutylammonium bromide or benzyltriethylammonium chloride; and / or, the amount of the catalyst added is 2% by mass of aniline or its derivatives; And / or, the stirring reaction temperature is 30 to 50° C., and the stirring reaction time is 24 to 36 hours; And / or, the first purification refers to distillation under reduced pressure at 120°C.

9. The short-process printing process for polyester-cotton blended fabric according to claim 6, characterized in that: The acid solution in step S3 is an aqueous solution containing 10% to 30% hydrogen chloride or acetic acid; and / or, the molar ratio of the diazo component to the coupling component is 1:1; And / or, the second purification comprises filtering the reaction solution at 5-10° C., then washing the filter cake with a saturated sodium chloride aqueous solution at 0-5° C. and water in sequence, and finally drying.

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