A polyester dyeing process

Abstract

The present application discloses a polyester dyeing process, which comprises the following steps: pretreatment: the polyester is subjected to alkali weight reduction treatment to obtain alkali weight-reduced polyester; dyeing: the alkali weight-reduced polyester is taken out and impregnated and rolled in a coating dye liquor, and then washed to obtain dyed polyester; color fixation: the dyed polyester is impregnated and rolled with an adhesive and dried to obtain finished polyester; the polyester dyeing process adopts a cationic modified coating dyeing process, and the coating dye liquor in the dyeing step comprises a cationic adhesive. When the polyester is dyed by adopting this process, the process flow is simple, and the obtained polyester has better levelness and better color fastness.

Description

Technical Field

[0001] This application relates to the field of textile printing and dyeing, and in particular to a polyester dyeing process. Background Art

[0002] Polyester is a synthetic fiber with a wide range of applications, large consumption, and high output. However, since polyester fiber is a hydrophobic synthetic fiber and lacks active groups that can bind to dyes, the dyeing performance of polyester fiber is generally poor.

[0003] Due to its good adaptability and complete color spectrum, pigment dyeing can meet the dyeing requirements of polyester fiber for various colors, so it is favored by people. However, in pigment dyeing, the pigment is coated on the surface of polyester fiber by the crosslinking and curing of a crosslinking agent and an adhesive. Since the dye carries anions, in the production process, polyester generally needs to be cation-modified to increase its adsorption capacity for dyes. However, due to the uneven surface charge after polyester modification, color difference is likely to occur. Summary of the Invention

[0004] In order to solve the problem of easy color difference in pigment dyeing, this application provides a polyester dyeing process.

[0005] A polyester dyeing process includes the following steps:

[0006] Pretreatment: Polyester is treated by alkali weight reduction to obtain alkali-weight-reduced polyester;

[0007] Dyeing: Take out the alkali-weight-reduced polyester and dip-roll it in the pigment dye liquor, and then wash it to obtain dyed polyester;

[0008] Fixing: The dyed polyester is dip-rolled with an adhesive and then dried to obtain finished polyester;

[0009] The polyester dyeing process adopts a cation-modified pigment dyeing process, and the pigment dye liquor in the dyeing step includes a cationic adhesive.

[0010] Preferably, in the dyeing step, it is washed twice with cold water, and the adhesive in the fixing step uses the cationic adhesive used in the pigment dye liquor; by weight, the components include: 1 part of polyester, 20 - 30 parts of pigment dye liquor, 20 - 30 parts of adhesive; in the dyeing step, the liquor pickup rate is 60 - 70%, the temperature is 60 - 70°C, in the fixing process, the liquor pickup rate is 60 - 70%, the drying temperature is 100 - 120°C, and the drying time is 5 - 10 min.

[0011] By adopting the above technical solution, since polyester is prone to carrying negative charges, introducing cations into the binder reduces the electrostatic repulsion between the coating and polyester, enabling the coating and polyester to combine through Coulomb force and making their combination tighter. Since dyes are usually anionic compounds and also carry negative charges, the dyes also combine more tightly with the binder in the coating through Coulomb force, improving the dyeing effect. Additionally, due to the modification of the coating with cations while the polyester remains unmodified, the charges distributed on the surface of the polyester are relatively uniform, so the dyeing effect is also relatively uniform, reducing the occurrence of color difference.

[0012] Preferably, the coating dye liquor, by weight, comprises the following components: 1 - 5 parts of pigment, 14 - 16 g of anti-migration agent, 20 - 40 parts of cation-modified binder, 800 - 1200 parts of deionized water, 3 - 6 g of emulsifier, and the cation-modified binder is a hyperbranched-modified cationic waterborne polyurethane.

[0013] By adopting the above technical solution, the hyperbranched structure enables the cationic groups to be dispersed in space in a three-dimensional rather than linear structure, increasing the contact area between the coating and polyester, making the combination of the coating and polyester tighter, and further improving the dyeing performance of the coating. After the polyester undergoes alkali weight reduction treatment, the gaps between polyester fibers become larger, and a large number of pits will also appear on the surface of the polyester fibers. The multiple branched structures of the hyperbranched structure can extend into the gaps between polyester fibers and bring the dyes into the interior of the polyester, solving the problem that due to the too large molecular weight of the hyperbranched structure, its dyeing is only on the surface of the polyester, resulting in the inability to obtain polyester with good coloring performance and color strength.

[0014] Typical but non-limiting, the pigment is selected as Red FR Conc, and the emulsifier is selected as DNS-86.

[0015] Preferably, the weight of the pigment is 2 - 3 parts, and the pigment is subjected to superfine treatment.

[0016] By adopting the above technical solution, the pigment is subjected to superfine treatment to obtain pigments with smaller particle sizes, improving the dyeing uniformity, and making it easier for the pigment to combine with the cation-modified binder, enhancing the coloring power and color strength of the coating dye liquor.

[0017] Preferably, the cation-modified binder is a hyperbranched-modified cationic waterborne polyurethane, which, by weight, comprises the following components: 20 - 35 parts of polyol, 10 parts of isocyanate, 0.5 - 1.5 parts of halogen chain extender, 0.5 - 1.5 parts of hydrophilic chain extender, 3 - 5 g of chain extender, 0.1 - 0.2 g of catalyst, 0.5 - 1.5 g of neutralizer, 0.5 - 2 g of end-hydroxyl hyperbranched polymer (HAPE).

[0018] Preferably, the polyol is selected from one or more of polyester polyol, polyether polyol, polycarbonate polyol, and polycaprolactone polyol;

[0019] The isocyanate is selected from one or more of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and polyphenyl polymethylene polyisocyanate.

[0020] Typically but not limited to, the polyol is selected from polyethylene glycol 200 and polyethylene glycol 400; the chain extender is 1,4-butanediol; the hydrophilic chain extender is dimethylolpropionic acid (DMPA); the halogen chain extender is 2,3-dibromosuccinic acid; the neutralizer is triethylamine; the catalyst is dibutyltin dilaurate.

[0021] By adopting the above technical solutions, the hydrophilic chain extender introduces hydrophilic groups to improve the water solubility of the coating dye solution; the halogen chain extender introduces halogens, and subsequent acid-base neutralization forms cationic groups; the terminal hydroxyl groups in the terminal hydroxyl hyperbranched polymer can combine with isocyanate groups to form hyperbranched waterborne polyurethane. The hyperbranched waterborne polyurethane has internal cavities that can encapsulate pigments; the pigments are superfine-treated to form smaller particle sizes, and it is easy to aggregate due to their too small surface free energy. However, the branches of the hyperbranched waterborne polyurethane do not entangle, so that the pigments encapsulated in the internal cavities can be dispersed evenly with smaller particle sizes, improving the level dyeing property of the coating dye solution. Through the hyperbranched structure, the hydrophilic groups and active groups are dispersed in space in a three-dimensional rather than linear structure, improving the water solubility of the binder and further improving the affinity between polyester and the coating, thus improving the dyeing performance of the coating.

[0022] Preferably, the isocyanate is an aliphatic isocyanate.

[0023] Typically but not limited to, the aliphatic isocyanate is isophorone diisocyanate.

[0024] By adopting the above technical solutions, although the waterborne polyurethane has advantages such as good flexibility and good adhesion, the dyed polyester finished products are evenly dyed and have a soft handfeel; however, the waterborne polyurethane is prone to yellowing. Therefore, an aliphatic isocyanate is preferably used. It does not have a benzene ring, and the waterborne polyurethane made from it is not easy to yellow, reducing the impact on the finished polyester. And isophorone diisocyanate is non-toxic, which can reduce subsequent wastewater treatment and improve the efficiency of the dyeing process.

[0025] Preferably, the terminal hydroxyl hyperbranched polymer (HAPE), by weight, comprises the following components: 10 parts of diethanolamine, 15-17 parts of methyl acrylate, 75-90 parts of trimethylolpropane, and 2-3 parts of catalyst.

[0026] Typically but not limited to, the catalyst is p-toluenesulfonic acid.

[0027] By adopting the above technical solution, the ratio of the hydroxyl-terminated hyperbranched polymer is optimized, so that the weight ratio of trimethylolpropane to diethanolamine is maintained at 1:7.5 - 9, resulting in a relatively high yield of the final HAPE product and reducing the occurrence of other side reactions.

[0028] Preferably, the preparation method of the hydroxyl-terminated hyperbranched polymer (HAPE) includes the following steps:

[0029] Monomer preparation: Diethanolamine is added to methanol and stirred until dissolved, then methyl acrylate is added. After the reaction, vacuum filtration is carried out to obtain the branched monomer.

[0030] Nucleation and chain extension: The branched monomer and trimethylolpropane are blended, and a catalyst is added to react to obtain the hydroxyl-terminated hyperbranched polymer (HPAE).

[0031] Preferably, in the monomer preparation step, after diethanolamine is completely dissolved by stirring, methyl acrylate is added. The reaction time is 3 - 4 h, and the reaction temperature is 35 - 45 °C; in the nucleation and chain extension step, the reaction temperature is 100 - 140 °C, and the reaction time is 2 - 4 h.

[0032] By adopting the above technical solution, with trimethylolpropane as the central core.

[0033] Preferably, the coating dye, by weight, further includes the following component: 0.5 - 2 g of nano-silica.

[0034] By adopting the above technical solution, nano-silica can be dispersed in the internal cavities of the hyperbranched structure, reducing the agglomeration phenomenon of the nano-materials. Moreover, nano-silica can penetrate into the interior of the polyester fiber along with the binder and adhere to the pits formed on the surface of the polyester, forming hydrogen bonds or electrostatic interactions with the pigments, further improving the dyeing fastness. In addition, nano-silica can provide a certain degree of hydrophobicity, improving the water resistance of the polyester and further enhancing the dyeing fastness.

[0035] Preferably, the preparation method of the cationic modified binder includes the following steps:

[0036] Pre-polymerization: Polyol is dehydrated, and isocyanate and a catalyst are added to react to obtain a pre-polymer.

[0037] Chain extension: A chain extender, a hydrophilic chain extender, and a halogen chain extender are added to the pre-polymer to react to obtain a cationic aqueous polyurethane; Hyperbranched modification: The cationic aqueous polyurethane and the hydroxyl-terminated hyperbranched polymer are blended, and then a neutralizing agent is added to obtain the cationic modified binder.

[0038] Preferably, the dehydration conditions in the prepolymerization step are as follows: temperature 100 - 120°C, pressure 0.05 - 0.07 MPa, nitrogen is passed through, and the dehydration time is 1 - 2 h; the reaction conditions in the prepolymerization step are: reaction time 4 - 6 h, reaction temperature 35 - 45°C; the reaction conditions in the chain extension reaction are: temperature 90 - 110°C, reaction time 2 - 3 h; the reaction conditions for hyperbranched modification are: blending reaction, temperature 60 - 70°C, reaction time 1 - 2 h; after adding the neutralizing agent, the temperature is adjusted to 25 - 35°C, and the reaction time is 0.5 - 1.5 h.

[0039] By adopting the above technical solution, halogen atoms are introduced in the chain extension step, and then triethylamine is added in the hyperbranched modification step to form a quaternary ammonium salt. The addition of triethylamine can also reduce the hydrolysis of the cationic modified binder after hyperbranched modification, so that the coating has good dyeing performance for a long time.

[0040] Preferably, the specific steps of the pretreatment are as follows: 10 g of polyester is put into 20 - 25 g of sodium hydroxide solution, the temperature is adjusted to 70 - 80°C, and it is left standing for 1 - 2 h to obtain alkali - deweighted polyester.

[0041] Preferably, the parameters of the alkali - deweighting treatment are optimized to improve the dyeing performance of polyester.

[0042] In summary, the present application has the following beneficial effects:

[0043] 1. Prepare a cationic hyperbranched water - borne polyurethane as a cationic modified binder, which is combined with materials such as pigments and nano - silica. After dyeing polyester, it has good leveling property, color fastness and color strength.

[0044] 2. Perform alkali - deweighting pretreatment on polyester to cooperate with the coating dyeing solution to form better dyeing performance. Specific Embodiments

[0045] The following further elaborates the present application in detail with reference to examples.

[0046] Preparation Examples of Raw Materials and / or Intermediates

[0047] Preparation of Hydroxyl - terminated Hyperbranched Polymer (HAPE)

[0048] Preparation Example 0 - 1, a preparation method of a hydroxyl - terminated hyperbranched polymer (HAPE), adopts the following steps:

[0049] Monomer preparation: Add 10 g of diethanolamine to 20 ml of methanol and stir until all the diethanolamine is dissolved, then add 16 g of methyl acrylate and react at 40°C for 3.5 h, and then perform vacuum filtration to obtain the branched monomer;

[0050] Nucleation and chain extension: Blend the branched monomer with 88 g of trimethylolpropane, add 2.5 g of p-toluenesulfonic acid, and react at 120 °C for 3 h to obtain HAPE.

[0051] Preparation Example 0-2, a method for preparing a hydroxyl-terminated hyperbranched polymer (HAPE), comprising the following steps:

[0052] Monomer preparation: Add 10 g of diethanolamine to 20 ml of methanol and stir until the diethanolamine is completely dissolved. Then add 17 g of methyl acrylate and react at 45 °C for 3 h. Then perform vacuum filtration to obtain the branched monomer.

[0053] Nucleation and chain extension: Blend the branched monomer with 90 g of trimethylolpropane, add 3 g of p-toluenesulfonic acid, and react at 140 °C for 2 h to obtain HAPE.

[0054] Preparation Example 0-3, a method for preparing a hydroxyl-terminated hyperbranched polymer (HAPE), comprising the following steps:

[0055] Monomer preparation: Add 10 g of diethanolamine to 20 ml of methanol and stir until the diethanolamine is completely dissolved. Then add 15 g of methyl acrylate and react at 35 °C for 4 h. Then perform vacuum filtration to obtain the branched monomer.

[0056] Nucleation and chain extension: Blend the branched monomer with 75 g of trimethylolpropane, add 2 g of p-toluenesulfonic acid, and react at 100 °C for 4 h to obtain HAPE.

[0057] Preparation Example 0-4, a method for preparing a hydroxyl-terminated hyperbranched polymer (HAPE), which is different from Preparation Example 0-1 in that the mass of trimethylolpropane is 105 g, that is, by weight, the weight portion is 105 parts.

[0058] Preparation Example 0-5, a method for preparing a hydroxyl-terminated hyperbranched polymer (HAPE), which is different from Preparation Example 0-1 in that the mass of trimethylolpropane is 50 g, that is, by weight, the weight portion is 50 parts.

[0059] Preparation of cationic modified binder

[0060] Preparation Example 1-1, a method for preparing a cationic modified binder, comprising the following steps:

[0061] Prepolymerization: Take 28 g of polyethylene glycol 200, dehydrate under nitrogen at 110 °C and 0.06 MPa for 1.5 h; add 10 g of isophorone diisocyanate and 0.15 g of dibutyltin dilaurate, and react at 40 °C for 5 h to obtain the prepolymer.

[0062] Chain extension: Add 4 g of 1,4-butanediol, 1 g of 2,3-dibromosuccinic acid and 1 g of dimethylolpropionic acid to the prepolymer, and react at 100 °C for 2.5 h to obtain cationic aqueous polyurethane;

[0063] Hyperbranched modification: Blend the cationic aqueous polyurethane with 1.3 g of HAPE, react at 65 °C for 1.5 h, then adjust the temperature to 30 °C, and add 1 g of triethylamine and react for 1 h to obtain a cationic modified adhesive.

[0064] Among them, HAPE comes from Preparation Example 0-1.

[0065] Preparation Example 1-2, a method for preparing a cationic modified adhesive, comprising the following steps:

[0066] Prepolymerization: Take 35 g of polyethylene glycol 200, dehydrate by passing nitrogen at 120 °C and 0.05 MPa for 1 h; add 10 g of isophorone diisocyanate and 0.2 g of dibutyltin dilaurate, and react at 45 °C for 4 h to obtain a prepolymer;

[0067] Chain extension: Add 5 g of 1,4-butanediol, 1.5 g of 2,3-dibromosuccinic acid and 0.5 g of dimethylolpropionic acid to the prepolymer, and react at 110 °C for 2 h to obtain cationic aqueous polyurethane;

[0068] Hyperbranched modification: Blend the cationic aqueous polyurethane with 2 g of HAPE, react at 70 °C for 1 h, then adjust the temperature to 35 °C, and add 1.5 g of triethylamine and react for 1.5 h to obtain a cationic modified adhesive.

[0069] Among them, HAPE comes from Preparation Example 0-2.

[0070] Preparation Example 1-3, a method for preparing a cationic modified adhesive, comprising the following steps:

[0071] Prepolymerization: Take 20 g of polyethylene glycol 400, dehydrate by passing nitrogen at 100 °C and 0.07 MPa for 2 h; add 10 g of isophorone diisocyanate and 0.1 g of dibutyltin dilaurate, and react at 35 °C for 6 h to obtain a prepolymer;

[0072] Chain extension: Add 3 g of 1,4-butanediol, 0.5 g of 2,3-dibromosuccinic acid and 1.5 g of dimethylolpropionic acid to the prepolymer, and react at 90 °C for 3 h to obtain cationic aqueous polyurethane;

[0073] Hyperbranched modification: Blend the cationic aqueous polyurethane with 0.5 g of HAPE, react at 60 °C for 2 h, then adjust the temperature to 25 °C, and add 0.5 g of triethylamine and react for 0.5 h to obtain a cationic modified adhesive.

[0074] Among them, HAPE comes from Preparation Example 0-3.

[0075] Preparation Example 1-4, a method for preparing a cation-modified binder, which is different from Preparation Example 1-1 in that the HAPE is from Preparation Example 0-4.

[0076] Preparation Example 1-5, a method for preparing a cation-modified binder, which is different from Preparation Example 1-1 in that the HAPE is from Preparation Example 0-5.

[0077] Preparation Example 1-6, a method for preparing a cation-modified binder, which is different from Preparation Example 1-1 in that isophorone diisocyanate is replaced with toluene diisocyanate.

[0078] Preparation Example 1-7, a method for preparing a cation-modified binder, which is different from Preparation Example 1-1 in that the mass of HAPE is 4 g, that is, by weight fraction, the weight part of HAPE is 4 parts.

[0079] Preparation Example 1-8, a method for preparing a cation-modified binder, which is different from Preparation Example 1-1 in that dimethylolpropionic acid is replaced with an equal amount of 1,4-butanediol. (That is, no hydrophilic chain extender is added)

[0080] Preparation Example 1-9, a method for preparing a cation-modified binder, comprising the following steps:

[0081] Pre-polymerization: Take 28 g of polyethylene glycol 200, dehydrate it by passing nitrogen at 110 °C and 0.06 MPa for 1.5 h; add 10 g of isophorone diisocyanate and 0.15 g of dibutyltin dilaurate, and react at 40 °C for 5 h to obtain a prepolymer;

[0082] Chain extension: Add 4 g of 1,4-butanediol, 1 g of 2,3-dibromosuccinic acid and 1 g of dimethylolpropionic acid to the prepolymer, react at 100 °C for 2.5 h, then adjust the temperature to 30 °C, and add 1 g of triethylamine and react for 1 h to obtain a cation-modified binder. (That is, no hyperbranched modification is carried out)

[0083] Preparation Example 1-10, a method for preparing a cation-modified binder, which is different from Preparation Example 1-9 in that dimethylolpropionic acid is replaced with an equal amount of 1,4-butanediol. (In the case of not carrying out hyperbranched modification, no hydrophilic chain extender is added) Preparation Example 1-11, a method for preparing a cation-modified binder, which is different from Preparation Example 1-1 in that 2,3-dibromosuccinic acid is replaced with an equal amount of 1,4-butanediol.

[0084] Preparation of the coating dye liquor

[0085] Preparation Example 2-1, a preparation process of a coating dyeing solution, adopts the following steps: Take 2.5 g of Pigment Red FR Conc, 15 g of anti-migration agent, 30 g of cation-modified binder, 1.3 g of nano-silica and 800 g of deionized water and mix them together. Then add 4.5 g of DNS-86 and stir at 1000 r / min for 10 min to obtain the coating dyeing solution.

[0086] Among them, the cation-modified binder comes from Preparation Example 1-1, and the step of superfine grinding of the pigment is: take 2.5 g of the pigment and place it in a high-pressure high-shear microfluidic crushing device for treatment to obtain.

[0087] Preparation Example 2-2, a preparation process of a coating dyeing solution, adopts the following steps: Take 3 g of Pigment Red FR Conc, 16 g of anti-migration agent, 40 g of cation-modified binder, 2 g of nano-silica and 1200 g of deionized water and mix them together. Then add 6 g of DNS-86 and stir at 1200 r / min for 10 min to obtain the coating dyeing solution.

[0088] Among them, the cation-modified binder comes from Preparation Example 1-2, and the step of superfine grinding of the pigment is: take 2.5 g of the pigment and place it in a high-pressure high-shear microfluidic crushing device for treatment to obtain.

[0089] Preparation Example 2-3, a preparation process of a coating dyeing solution, adopts the following steps: Take 2 g of Pigment Red FR Conc, 14 g of anti-migration agent, 20 g of cation-modified binder, 0.5 g of nano-silica and 1000 g of deionized water and mix them together. Then add 3 g of DNS-86 and stir at 80000 r / min for 10 min to obtain the coating dyeing solution.

[0090] Among them, the cation-modified binder comes from Preparation Example 1-3, and the step of superfine grinding of the pigment is: take 2.5 g of the pigment and place it in a high-pressure high-shear microfluidic crushing device for treatment to obtain.

[0091] Preparation Example 2-4, a preparation process of a coating dyeing solution, is different from Preparation Example 2-1 in that the cation-modified binder comes from Preparation Example 1-4.

[0092] Preparation Example 2-5, a preparation process of a coating dyeing solution, is different from Preparation Example 2-1 in that the cation-modified binder comes from Preparation Example 1-5.

[0093] Preparation Example 2-6, a preparation process of a coating dyeing solution, is different from Preparation Example 2-1 in that the cation-modified binder comes from Preparation Example 1-6.

[0094] Preparation Example 2-7, a preparation process of a coating dyeing solution, is different from Preparation Example 2-1 in that the cation-modified binder comes from Preparation Example 1-7.

[0095] Preparation Example 2-8, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the cation-modified binder is from Preparation Example 1-8.

[0096] Preparation Example 2-9, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the cation-modified binder is from Preparation Example 1-9.

[0097] Preparation Example 2-10, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the cation-modified binder is from Preparation Example 1-10.

[0098] Preparation Example 2-11, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the mass of the pigment is 5 g, that is, by weight, the weight portion of the pigment is 5 portions.

[0099] Preparation Example 2-12, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the mass of the pigment is 1 g, that is, by weight, the weight portion of the pigment is 1 portion.

[0100] Preparation Example 2-13, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the pigment is not superfine-treated.

[0101] Preparation Example 2-14, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the nano-silica is replaced with an equal amount of cation-modified binder.

[0102] Preparation Example 2-15, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-9 in that the nano-silica is replaced with an equal amount of cation-modified binder.

[0103] Preparation Example 2-16, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-9 in that the pigment is not superfine-treated.

[0104] Preparation Example 2-17, a preparation process of a coating dyeing solution, which is different from Preparation Example 2-1 in that the cation-modified binder is from Preparation Example 1-11.

[0105] Example

[0106] Example 1, a polyester dyeing process, comprising the following steps:

[0107] Pretreatment: 10 g of polyester is put into 23 g of sodium hydroxide solution, the temperature is adjusted to 75 °C, and it is left standing for 1.5 h to obtain alkali-treated polyester; Dyeing: The alkali-weight-reduced polyester is padded with 250 g of the coating dyeing solution at 80 °C for 5 min, the liquor ratio is 65%, and it is washed twice with cold water to obtain dyed polyester.

[0108] Fixation: After dyeing, the polyester is padded with 250 g of cationic modified binder for 2 min and dried at 110 °C for 8 min to obtain the finished polyester.

[0109] Among them, the coating dye liquor is from Preparation Example 2-1, and the cationic modified binder is from Preparation Example 1-1.

[0110] Example 2, a polyester dyeing process, includes the following steps:

[0111] Pretreatment: 10 g of polyester is put into 20 g of sodium hydroxide solution, the temperature is adjusted to 80 °C, and it is left standing for 1 h to obtain alkali-treated polyester; Dyeing: The alkali-deweighted polyester is padded with 300 g of coating dye liquor at 70 °C for 5 min, the liquor pickup rate is 70%, and it is washed twice with cold water to obtain the dyed polyester.

[0112] Fixation: The dyed polyester is padded with 200 g of cationic modified binder for 2 min and dried at 120 °C for 5 min to obtain the finished polyester.

[0113] Among them, the coating dye liquor is from Preparation Example 2-2, and the cationic modified binder is from Preparation Example 1-2.

[0114] Example 3, a polyester dyeing process, includes the following steps:

[0115] Pretreatment: 10 g of polyester is put into 20 g of sodium hydroxide solution, the temperature is adjusted to 70 °C, and it is left standing for 2 h to obtain alkali-treated polyester; Dyeing: The alkali-deweighted polyester is padded with 200 g of coating dye liquor at 60 °C for 5 min, the liquor pickup rate is 70%, and it is washed twice with cold water to obtain the dyed polyester.

[0116] Fixation: The dyed polyester is padded with 300 g of cationic modified binder for 2 min and dried at 100 °C for 10 min to obtain the finished polyester.

[0117] Among them, the coating dye liquor is from Preparation Example 2-3, and the cationic modified binder is from Preparation Example 1-3.

[0118] Example 4, a polyester dyeing process, is different from Example 1 in that the coating dye liquor is from Preparation Example 2-4 and the cationic modified binder is from Preparation Example 1-1.

[0119] Example 5, a polyester dyeing process, is different from Example 1 in that the coating dye liquor is from Preparation Example 2-5 and the cationic modified binder is from Preparation Example 1-1.

[0120] Example 6, a polyester dyeing process, is different from Example 1 in that the coating dye liquor is from Preparation Example 2-6 and the cationic modified binder is from Preparation Example 1-1.

[0121] Example 7. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-7 and the cationic modified binder is from Preparation Examples 1-1.

[0122] Example 8. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-8 and the cationic modified binder is from Preparation Examples 1-1.

[0123] Example 9. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-9 and the cationic modified binder is from Preparation Examples 1-1.

[0124] Example 10. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-10 and the cationic modified binder is from Preparation Examples 1-1.

[0125] Example 11. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-11 and the cationic modified binder is from Preparation Examples 1-1.

[0126] Example 12. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-12 and the cationic modified binder is from Preparation Examples 1-1.

[0127] Example 13. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-13 and the cationic modified binder is from Preparation Examples 1-1.

[0128] Example 14. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-14 and the cationic modified binder is from Preparation Examples 1-1.

[0129] Example 15. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-15 and the cationic modified binder is from Preparation Examples 1-1.

[0130] Example 16. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-16 and the cationic modified binder is from Preparation Examples 1-1.

[0131] Comparative Example

[0132] Comparative Example 1. A polyester dyeing process, which is different from Example 1 in that the coating dye liquor is from Preparation Examples 2-17.

[0133] Comparative Example 2. A polyester dyeing process, which is different from Example 1 in that the polyester is not pretreated (i.e., alkali weight reduction treatment) and directly undergoes the dyeing step.

[0134] Comparative Example 3, a polyester dyeing process, comprises the following steps:

[0135] Dyeing: Take 10 g of cation-modified polyester, pad the coating dye liquor at 60 °C for 5 min, the liquor pickup is 65%, and wash twice with cold water to obtain the dyed polyester;

[0136] Fixing: Take the dyed polyester, put it into a solution containing 2 g of fixing agent, 1 g of acetic acid and 97 g of water, heat it in a water bath at 95 °C for 25 min, then wash, dehydrate and dry to obtain the finished polyester.

[0137] The coating dye liquor is prepared by mixing 1 g of Pigment Red FR Conc, 9 g of X-995S dispersant, 10 g of AZN anti-migration agent and 20 g of 734E binder, and then adding water to 1 L.

[0138] Comparative Example 4, a polyester dyeing process, is different from Comparative Example 3 in that the mass of Pigment Red FR Conc is 2 g.

[0139] Performance detection test

[0140] Perform performance tests on the polyamide materials of Examples 1-16 and Comparative Examples 1-4, and the test results are shown in Table 1.

[0141] Test 1: Determination of K / S value. The apparent depth of the fabric is characterized by the K / S value. Using the X-Rite 8200 computer color measurement and matching system, measure at a D65 light source and a 10° viewing angle. Take 6 measurements for the K / S value of each sample and take the average value.

[0142] Test 2: Determination of levelness. Using the X-Rite SP62 integrating sphere spectrophotometer, select 10 points randomly on the dyed sample for measurement and take the average value. The smaller the value, the better the color difference.

[0143] Test 3: Color fastness. The color fastness to rubbing is tested according to GB / T3920-2008 "Textiles - Tests for color fastness - Color fastness to rubbing".

[0144] Table 1: Test results

[0145]

[0146]

[0147] It can be seen from combining Examples 1-5 and Example 7 and Table 1 that during the preparation process of the hydroxyl-terminated hyperbranched polymer (HAPE), controlling the mass of trimethylolpropane as the core has a certain impact on the function of HAPE; the addition amount of HAPE also has a certain impact on the dyeing effect. The reason is that if there are too many nucleating agents, too few branched structures are generated, which affects the subsequent grafting of polyurethane and the hyperbranched structure of the prepared hyperbranched modified polyurethane, thereby affecting the dyeing performance of the coating dye liquor. Too few nucleating agents will result in too many branched structures, affecting the excessive molecular weight of the hyperbranched polyurethane, and the coating dye liquor cannot enter the interior of the polyester, affecting the dyeing performance. An excessive addition amount of HAPE will also cause the molecular weight of the hyperbranched polyurethane to be too large.

[0148] It can be seen from combining Examples 1, 8-10 that not introducing hydrophilic groups into the binder and not modifying the polyurethane with a hyperbranched structure both have an impact on the dyeing performance of the coating dye liquor, and there is a synergistic effect between introducing hydrophilic groups and hyperbranched structure modification. The reason is that introducing hydrophilic groups can improve the affinity between the coating dye liquor and polyester and enhance its level dyeing property. The hyperbranched structure can encapsulate pigment small molecules, making the dyeing effect better and more uniform. After introducing the hyperbranched structure, the hydrophilic groups can exist in a three-dimensional structure between the internal fibers of the polyester, further improving the affinity between the coating dye liquor and polyester.

[0149] It can be seen from combining Examples 1, 11-13 and Example 16 and Table 1 that the dosage of the pigment has a certain impact on the dyeing performance of the coating dye liquor, and there is a certain synergistic effect between the hyperbranched structure and the pigment. The reason is that if too much pigment is used, the cationic modified binder cannot completely encapsulate the pigment, resulting in a decrease in level dyeing property. The internal cavities of the hyperbranched structure can carry more pigments within a certain space, improving the dyeing performance of the coating dye liquor.

[0150] It can be seen from combining Examples 1, 14-15 and Table 1 that nano-silica will affect the color fastness of the finished polyester, and there is also a certain compatibility effect between nano-silica and the hyperbranched structure. The reason is that nano-silica can enter the space between the internal fibers of the polyester, acting as a bridge between the polyester and the coating dye liquor and improving the bonding fastness between the polyester and the coating dye liquor. Nano-silica can improve the hydrophobicity of the polyester, enhancing the wash fastness of the polyester. The hyperbranched structure can carry nano-silica into the interior of the polyester, further enhancing the effect of nano-silica.

[0151] It can be seen from combining Examples 1 and Comparative Example 1 and Table 1 that the bonding effect between the unmodified cationic coating dye liquor and the polyester is not good. The reason is that both the polyester and the pigment carry anions, and their bonding performance is poor.

[0152] Combined with Example 1 and Comparative Example 2 and with reference to Table 1, it can be seen that the dyeing performance of polyester without alkali weight reduction treatment decreases significantly. The reason is that after the alkali weight reduction treatment of polyester, the gaps between polyester fibers become larger, and a large number of pits will appear on the surface of polyester fibers. Multiple branched chains of the hyperbranched structure can extend into the polyester fibers, which can further exert the effects of nano-silica, cationic groups, and hydrophilic groups, improve the dyeing effect of the coating dye liquor, and improve the color fastness of polyester.

[0153] Combined with Example 1, Example 11 and Comparative Examples 2-3 and with reference to Table 1, it can be seen that compared with dyeing after cationic modification of polyester, dyeing the fibers with cationic modified coating not only simplifies the process and saves energy, but also improves the dyeing performance and color fastness. Especially when using the coating dye liquor itself, the hyperbranched modified cationic polyurethane can combine with more pigments under the same quality, further improving the dyeing performance of the coating dye liquor.

[0154] This specific embodiment is only an interpretation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A polyester dyeing process, characterized in that, It includes the following steps: Pretreatment: Polyester is subjected to alkali weight reduction treatment to obtain alkali weight-reduced polyester; Dyeing: Take out the alkali weight-reduced polyester, dip it in the coating dye liquor, and then wash it to obtain dyed polyester; Fixing: The dyed polyester is dip-coated with an adhesive and dried to obtain finished polyester; The polyester dyeing process adopts a cationic modified coating dyeing process. The coating dye liquor in the dyeing step includes the following components by weight: 1-5 parts of pigment, 14-16 parts of anti-migration agent, 20-40 parts of cationic modified adhesive, 800-1200 parts of deionized water, 3-6 g of emulsifier, and 0.5-2 parts of nano-silica. The cationic modified adhesive is a cationic waterborne polyurethane modified by hyperbranched modification, and includes the following components by weight: 20-35 parts of polyol, 10 parts of isophorone diisocyanate, 0.5-1.5 parts of halogen chain extender, 0.5-1.5 parts of hydrophilic chain extender, 3-5 parts of chain extender, 0.1-0.2 parts of catalyst, 0.5-1.5 parts of neutralizer, and 0.5-2 parts of hydroxyl-terminated hyperbranched polymer; The hydroxyl-terminated hyperbranched polymer includes the following components by weight: 10 parts of diethanolamine, 15-17 parts of methyl acrylate, 75-90 parts of trimethylolpropane, and 2-3 parts of catalyst. Its preparation method includes the following steps: (1) Monomer preparation: Add diethanolamine to methanol and stir to dissolve, then add methyl acrylate. After reaction, vacuum filter to obtain a branched monomer; (2) Nucleation and chain extension: Blend the branched monomer with trimethylolpropane, add a catalyst, and react to obtain a hydroxyl-terminated hyperbranched polymer; The preparation method of the cationic modified adhesive includes the following steps: (1) Prepolymerization: Take polyol, dehydrate it by passing nitrogen at 100-120°C and 0.05-0.07 MPa for 1-2 h, add isophorone diisocyanate and a catalyst, and react at 35-45°C for 4-6 h to obtain a prepolymer; (2) Chain extension: Add a chain extender, a hydrophilic chain extender, and a halogen chain extender to the prepolymer, and react at 90-110°C for 2-3 h to obtain a cationic waterborne polyurethane; (3) Hyperbranched modification: Blend the cationic waterborne polyurethane with the hydroxyl-terminated hyperbranched polymer, react at 60-70°C for 1-2 h, add a neutralizer, and adjust the temperature to 25-35°C to react for 0.5-1.5 h to obtain the cationic modified adhesive.

2. The polyester dyeing process according to claim 1, characterized in that, The weight of the pigment is 2-3 parts, and the pigment is subjected to superfine treatment.

3. A polyester dyeing process according to claim 1, characterized in that, The specific steps of the pretreatment are as follows: Put 10 g of polyester into 20-25 g of sodium hydroxide solution, adjust the temperature to 70-80°C, let it stand for 1-2 h, take it out, wash it, and dry it to obtain alkali-treated polyester.

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