Preparation method and application of cationic modifier for cellulose fibers
By using secondary amines, dichloroalkyl ethers and epoxypropane, the problem of high content of trimethylamine hydrochloride in the prior art is solved, and the dyeing efficiency and dyeing fastness are improved. Improved the quality of cellulose fiber fabrics.
Patent Information
- Application Number
- CN202411611238.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-02-14
AI Technical Summary
The cationic etherifying agent used in the prior art has a high content of trimethylamine hydrochloride, which causes the quality of dyed cotton fabrics to be affected, and the cationic etherifying agent is easily decomposed to form trimethylamine hydrochloride during high temperature dyeing, which affects the dyeing uniformity and Color fastness.
Using secondary amine, dichloroalkyl ether and epoxychlorohydrin as the main raw materials, biquaternary ammonium salt cationic modifiers were prepared by regulating the reaction temperature and using a catalyst, which avoided the introduction of trimethylamine hydrochloride and improved the staining. Efficiency and dyeing fastness.
Without introducing trimethylamine hydrochloride, the thermal stability and dyeing efficiency of the cationic modifier are improved, the binding force between cellulose fibers and dyes is enhanced, the quality of dyed fabrics is improved, and the fishy smell is avoided. produce.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of biofiber modification, and in particular to a preparation method and application of a cationic modifier for cellulose fibers. Background Art
[0002] Cellulose fiber fabrics represented by cotton are soft to the touch, comfortable to wear, and have good hygroscopicity, air permeability and thermal insulation. They are widely used in the production of clothing, household goods, medical and sanitary products and industrial products, and are the main textile printing and dyeing materials. Direct dyes are dyes that can be heated and boiled in neutral and weakly alkaline media without the help of mordants. Using direct dyes to dye cotton fabrics has the advantages of simple dyeing process, low production cost and bright color. However, since direct dyes rely on the combination of hydrogen bonds and van der Waals forces between them and cotton fibers, they have low affinity and are prone to problems such as uneven dyeing and poor color fastness. Cationic etherifying agents can be used to modify cotton fibers so that the surface of cotton fibers is uniformly and stably charged with cationic charges. During the dyeing process, cotton fibers with cationic charges on the surface can form more stable covalent bonds with dyes, thereby improving the dyeing efficiency and dyeing uniformity of the dye.
[0003] In the prior art, cationic etherifying agents are mostly synthesized using trimethylamine or trimethylamine hydrochloride as raw materials. Since organic synthesis reactions are generally reversible reactions, the conversion rate of raw materials is difficult to reach 100%. Trimethylamine hydrochloride used directly or indirectly in the synthesis process is bound to remain as an impurity in the cationic etherifying agent. When cotton fabrics modified by cationic etherifying agents are dyed at high temperatures, the cationic etherifying agent will also decompose under heat to generate trimethylamine hydrochloride, resulting in excessive trimethylamine hydrochloride content in the cotton fabric, which directly affects the quality of the dyed cotton fabric. Summary of the invention
[0004] Aiming at the problem that the cationic etherifying agent trimethylamine hydrochloride used in the prior art has a high content, the present invention provides a preparation method and application of a cationic modifier for cellulose fiber, wherein a diquaternary ammonium salt cationic modifier with high activity is prepared using secondary amine, dichloroalkyl ether and epichlorohydrin as main raw materials, and the dyeing efficiency and dyeing fastness are improved without introducing trimethylamine hydrochloride.
[0005] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for preparing a cationic modifier for modifying cellulose fibers, comprising the following steps: Step 1: Add secondary amine, dichloroalkyl ether and the first catalyst into a reaction kettle, react at 30-100° C., the molar ratio of the secondary amine to the dichloroalkyl ether is 2-2.4:1, and the amount of the first catalyst added is 0.5%-5% of the sum of the mass of the secondary amine and the dichloroalkyl ether; Step 2: adjusting the pH value of the material in the reactor to 7.5-9.5, then adding the second catalyst into the reactor, and dripping epichlorohydrin into the reactor at 0-30°C, and keeping the temperature at 30-70°C for reaction after the dripping is completed, the molar ratio of epichlorohydrin to the secondary amine is 0.9-1.5:1, and the amount of the first catalyst added is 0.5%-8% of the sum of the mass of the secondary amine and the dichloroalkyl ether; Step 3: adjusting the pH value of the material in the reactor to 3.0-6.5, stopping the reaction, and obtaining a crude product of the cationic modifier; Step 4: distill the crude product of the cationic modifier under reduced pressure to obtain the cationic modifier.
[0006] Further, in step 1, the secondary amine is one or more of dimethylamine, diethylamine, N-methylethylamine, di-n-propylamine, diisopropylamine, N-methyl-n-propylamine, N-ethyl-n-propylamine, N-methylisopropylamine, and N-ethylisopropylamine. The dichloroalkyl ether is one or more of dichloromethyl ether, dichloroethyl ether, and dichloroisopropyl ether. The first catalyst is one or more of cuprous chloride, ferric oxide, aluminum oxide, and silicon dioxide.
[0007] Furthermore, in step 1, the pressure in the reactor is 0-10 kg, preferably 5-7 kg, and the reaction time is 2-10 h.
[0008] Furthermore, in step 2, the second catalyst is one or more of sodium sulfate, potassium sulfate, sodium sulfite, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium thiosulfate, potassium thiosulfate, sodium persulfate, and potassium persulfate.
[0009] Furthermore, in step 2, the dripping time of epichlorohydrin is controlled to be 3-10 hours. During the dripping of epichlorohydrin, a refrigerant is used to cool the reactor.
[0010] Furthermore, in step 2, the insulation reaction time is 3-24 hours.
[0011] Furthermore, in step 4, the temperature of the vacuum distillation is 50-90° C., the pressure of the vacuum distillation is -0.08 MPa to -0.15 MPa, and the diquaternary ammonium salt content of the obtained cationic modifier is greater than 50 wt %. In the present invention, the pressure of the vacuum distillation is the pressure relative to the environment.
[0012] In a second aspect, the present invention further provides an application of the cationic modifier prepared by the preparation method as described above in dyeing, comprising the following steps: Step S1: padding, using a small padder to perform two dips and two rolls on the cellulose fiber fabric in the modifying liquid; in the modifying liquid, the concentration of the cationic modifier is 3.5% (owf)-7.0% (owf), the concentration of the activator is 1.0% (owf)-2.5% (owf), and the concentration of the penetrant is 3-5g / L; in the two dips and two rolls, the rolling rate of the padder is 70%-80%, and the vehicle speed is 40-50m / min; Step S2: stacking, placing the impregnated cellulose fiber fabric in a plastic film for stacking, the stacking temperature is 25-35° C., and the stacking time is 10-24 hours; Step S3: washing and drying, washing the stacked cellulose fiber fabric to neutrality, and then drying to obtain modified cellulose fiber fabric, the washing temperature is 50-60°C, the drying temperature is 80-90°C, and the drying time is 5-10min; Step S4: putting the modified cellulose fiber fabric into a reactive dye solution, heating it to 60-70° C. for constant temperature dyeing to obtain a dyed fabric, wherein the amount of the reactive dye in the reactive dye solution is 1% (owf)-2% (owf); Step S5: sequentially subjecting the dyed fabric to a first water wash, a soap wash, a second water wash, and drying to obtain a finished fabric.
[0013] Furthermore, in step S5, the temperature of the first water wash and the second water wash are both 85-95°C, the time of the first water wash and the second water wash are both 2-5 minutes, the temperature of the soap wash is 90-95°C, the time of the soap wash is 2-5 minutes, and the amount of soap solution is 1-2g / L.
[0014] Furthermore, the cellulose fibers include cotton fibers, hemp fibers, wool fibers, bamboo fibers, silk fibers and modal fibers.
[0015] The beneficial effects of the present invention are: The invention provides a preparation method and application of a cationic modifier for cellulose fiber. The reaction process of secondary amine, dichloroalkyl ether and epichlorohydrin is accelerated by regulating the reaction temperature and using a catalyst, thereby improving the reaction efficiency. The secondary amine, dichloroalkyl ether and epichlorohydrin are used as main raw materials. On the one hand, during the preparation of the cationic modifier, it is avoided to remove impurities and purify the intermediate product, thereby saving equipment investment and improving the yield. On the other hand, the preparation process of the cationic modifier is simplified without introducing trimethylamine hydrochloride, thereby improving the thermal stability of the cationic modifier. After the modified fabric is dyed, no fishy smell is generated, thereby improving the quality of the dyed fabric. The diquaternary ammonium salt cationic modifier is synthesized by regulating the ratio of the secondary amine, dichloroalkyl ether and epichlorohydrin and the synthesis process parameters. After the cationic modifier containing dicationic charges is introduced into the surface of the cellulose fiber, the probability of electrical neutralization between the cellulose fiber and the active dye molecule can be increased, thereby improving the dyeing performance of the active dye, thereby also improving the dyeing rate and color depth, and the dyeing fastness is not reduced. DETAILED DESCRIPTION
[0016] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0017] Example 1 A method for preparing a cationic modifier for modifying cellulose fibers comprises the following steps: Step 1: Add diethylamine and dichloromethyl ether into a reactor at a molar ratio of 2:1, and add a catalyst cuprous chloride (CuCl), the amount of cuprous chloride (CuCl) added is 2% of the total mass of diethylamine and dichloromethyl ether, seal the reactor and heat to 60°C for 6 hours to generate diether amine salt. During the reaction, the pressure in the reactor is 5 kg.
[0018] Step 2: Adjust the pH value of the material in the reactor to 8.0, then add sodium sulfite to the reactor, the amount of sodium sulfite added is 4% of the mass of diethylamine and dichloromethyl ether, use a refrigerant to reduce the temperature in the reactor to 20°C, slowly add epichlorohydrin to the reactor at 20°C, and control the drop time of epichlorohydrin to 6h. After the drop of epichlorohydrin is completed, the material in the reactor is turbid, and the material in the reactor is heated to 30°C for 18h, and the molar ratio of epichlorohydrin to diethylamine is 1.05:1.
[0019] Step 3: After the heat preservation reaction is completed, hydrochloric acid is added into the reactor to adjust the pH value of the material in the reactor to 5.0, terminate the reaction, and obtain a crude product of the cationic modifier; Step 4: subjecting the crude product of the cationic modifier to vacuum distillation to obtain the cationic modifier, the vacuum distillation temperature is 70° C., and the vacuum distillation pressure is -0.09 MPa.
[0020] The cationic modifier obtained in this example was detected by Fourier transform infrared spectroscopy, and the functional group was determined according to the infrared characteristic peak comparison table. After comparison with the spectrum of the target active substance, the specific structural formula of the active substance in the cationic modifier was determined as follows: .
[0021] Example 2 A method for preparing a cationic modifier for modifying cellulose fibers comprises the following steps: Step 1: Add di-n-propylamine and dichloroethyl ether into the reactor at a molar ratio of 2.2:1, and add catalyst iron oxide (Fe2O3). The amount of iron oxide (Fe2O3) added is 1% of the total mass of di-n-propylamine and dichloroethyl ether. Seal the reactor and heat to 70°C for constant temperature reaction for 5 hours to generate diether amine salt. During the reaction, the pressure in the reactor is 7 kg.
[0022] Step 2: Adjust the pH value of the material in the reactor to 7.8, then add potassium sulfite to the reactor, the amount of potassium sulfite added is 5% of the mass of di-n-propylamine and dichloroethyl ether, use refrigerant to reduce the temperature in the reactor to 22°C, slowly add epichlorohydrin to the reactor at 22°C, and control the drop time of epichlorohydrin to 5h. After the drop of epichlorohydrin is completed, the material in the reactor is turbid, and the material in the reactor is heated to 45°C for 15h, and the molar ratio of epichlorohydrin to di-n-propylamine is 1.2:1.
[0023] Step 3: After the heat preservation reaction is completed, hydrochloric acid is added into the reactor to adjust the pH value of the material in the reactor to 5.5, and the reaction is terminated to obtain a crude product of the cationic modifier; Step 4: subjecting the crude product of the cationic modifier to vacuum distillation to obtain the cationic modifier, the vacuum distillation temperature is 75° C., and the vacuum distillation pressure is -0.10 MPa.
[0024] The cationic modifier obtained in this example was detected by Fourier transform infrared spectroscopy, and the functional group was determined according to the infrared characteristic peak comparison table. After comparison with the spectrum of the target active substance, the specific structural formula of the active substance in the cationic modifier was determined as follows: .
[0025] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the diethylamine and dichloromethyl ether in step 1 are replaced by trimethylamine and hydrochloric acid, respectively, and the molar ratio of trimethylamine to hydrochloric acid is 1:1.
[0026] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the first catalyst is not used in step 1.
[0027] Comparative Example 3 The only difference between Comparative Example 3 and Example 1 is that in step 2, during the process of dropwise addition of epichlorohydrin, no refrigerant is used to cool the reactor.
[0028] Test Example 1 The contents of active substances in the cationic modifiers prepared in Examples 1-2 and Comparative Examples 1-3 were detected respectively according to the following methods. The detection results are shown in Table 1.
[0029] (1) Blank titration Accurately weigh 2.6-3.4g (accurate to 0.0002g) of the sample into a dry iodine volumetric flask, then add 60mL of distilled water and 3 drops of phenolphthalein indicator, and titrate with 0.1mol / L sodium hydroxide standard solution until a slightly reddish color is obtained as the end point.
[0030] Calculate the blank test value A using formula 1: (Formula 1), In formula 1, c3 is the concentration of the sodium hydroxide standard solution in the blank titration, 0.1 mol / L; V3 is the volume of 0.1 mol / L sodium hydroxide standard solution consumed by the blank sample, ml; w is the mass of the blank sample, g.
[0031] (2) Titration of active substance content Accurately weigh 1.0-1.1g (accurate to 0.0002g) of the sample into a dry iodine volumetric flask, then use a burette to add 10.0mL of 0.5mol / L sodium hydroxide standard solution into the iodine volumetric flask, add 10ml of distilled water, plug the stopper tightly, shake well, add 3 drops of phenolphthalein indicator after 10 minutes, and titrate with 0.1mol / L hydrochloric acid standard solution until the red color disappears, which is the end point.
[0032] The content X of the active substance in the sample is calculated using formula 2: ×100% (Formula 2), In formula 2, c1 is the concentration of sodium hydroxide standard solution, 0.5 mol / L; V1 is the volume of 0.5 mol / L sodium hydroxide standard solution consumed by the sample, ml; c2 is the concentration of the hydrochloric acid standard solution, 0.1 mol / L; V2 is the volume of 0.1 mol / L hydrochloric acid standard solution consumed by the sample, ml; m is the mass of the sample, g; M is the relative molecular weight of the active substance, g / mol Table 1 Test results of active substance content of cationic modifiers prepared in Examples 1-2 and Comparative Examples 1-3
[0033] As can be seen from Table 1, the content of active substances in the cationic modifiers prepared in Examples 1-2 and Comparative Example 1 is higher than 50%, while the content of active substances in Comparative Examples 2 and 3 is significantly lower than that in Examples 1-2 and Comparative Example 1, indicating that the present invention can significantly increase the content of active substances in the cationic modifier by regulating the process parameters in the preparation method.
[0034] Test Example 2 Alkaline solution was added to the cationic modifiers prepared in Examples 1-2 and Comparative Examples 1-3 for activation, and then the trimethylamine gas content on the upper layer of the liquid surface was detected using headspace gas phase. The detection results are shown in Table 2.
[0035] Table 2 Test results of trimethylamine gas content of cationic modifiers prepared in Examples 1-2 and Comparative Examples 1-3
[0036] It can be seen from Table 2 that when alkali solution is added to the cationic modifier prepared in Comparative Example 1 for activation, trimethylamine gas will be emitted, indicating that the cationic modifier prepared by using secondary amine, dichloroalkyl ether and epichlorohydrin as raw materials in the present invention will not decompose to produce trimethylamine after high-temperature heating, thereby reducing the possibility of residual fishy smell in the fabric after active dyeing.
[0037] Example 3 The cationic modifiers prepared in Examples 1-2 and Comparative Examples 1-3 were used to modify and dye pure cotton cellulose fiber knitted fabrics, respectively, in the following steps: Step S1: padding, using a small padder to perform two dips and two pads on the pure cotton cellulose fiber knitted fabric in the modifying liquid. In the modifying liquid, the concentration of the cationic modifier is 4.5% (owf), the concentration of caustic soda is 1.5% (owf), and the concentration of the non-ionic penetrant is 3g / L; in the two dips and two pads, the padder rolling rate is 70%, and the vehicle speed is 40m / min.
[0038] Step S2: stacking, placing the impregnated pure cotton cellulose fiber knitted fabric in a plastic film for stacking, the stacking temperature is 25° C., and the stacking time is 16 hours.
[0039] Step S3: washing and drying, washing the stacked pure cotton cellulose fiber knitted fabric to neutrality, and then drying to obtain modified cellulose fiber fabric, the washing temperature is 55° C., the drying temperature is 90° C., and the drying time is 10 min.
[0040] Step S4: putting the modified cellulose fiber fabric into a reactive dye solution, heating the temperature to 70°C at a heating rate of 2°C / min, and dyeing at a constant temperature for 25 minutes to obtain a dyed fabric, wherein the reactive dye in the reactive dye solution is reactive red B-2BF, the amount of the reactive dye is 1% (owf), and the bath ratio is 1:20.
[0041] Step S5: sequentially washing the dyed fabric with water for the first time, washing with soap, washing with water for the second time, and drying to obtain a finished fabric, wherein the temperature of the first washing and the second washing are both 90°C, the time of the first washing and the second washing are both 5 minutes, the temperature of the soap washing is 90°C, the time of the soap washing is 5 minutes, and the amount of soap solution is 2 g / L.
[0042] The color quantity, color fastness and fabric odor of the finished fabrics obtained by modifying and dyeing the pure cotton cellulose fiber knitted fabrics using the cationic modifiers prepared in Examples 1-2 and Comparative Examples 1-3 were tested respectively. The test results are shown in Table 3: Table 3 Fabric color fastness and odor test results after reactive dyeing of the embodiments and comparative examples
[0043] It can be seen from Table 3 that the finished fabric modified with the cationic modifier prepared in Example 1-2 has significantly improved apparent color quantity and color fastness after reactive dyeing, and the dyeing rate is greatly improved, indicating that the preparation method of the present invention can save the amount of dye, avoid the appearance of odor in the fabric after dyeing, and improve the overall quality of the fabric.
[0044] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily conceive of changes or substitutions within the technical scope disclosed by the present invention, and such changes or substitutions shall be within the scope of protection of the present invention.
Claims
1. A method for preparing a cationic modifier for cellulose fibers, characterized in that: The steps include: Step 1: Add secondary amine, dichloroalkyl ether and the first catalyst into a reaction kettle, react at 30-100° C., the molar ratio of the secondary amine to the dichloroalkyl ether is 2-2.4:1, and the amount of the first catalyst added is 0.5%-5% of the sum of the mass of the secondary amine and the dichloroalkyl ether; Step 2: adjusting the pH value of the material in the reactor to 7.5-9.5, then adding the second catalyst into the reactor, and dripping epichlorohydrin into the reactor at 0-30°C, and keeping the temperature at 30-70°C for reaction after the dripping is completed, the molar ratio of epichlorohydrin to the secondary amine is 0.9-1.5:1, and the amount of the second catalyst added is 0.5%-8% of the sum of the mass of the secondary amine and the dichloroalkyl ether; Step 3: adjusting the pH value of the material in the reactor to 3.0-6.5, stopping the reaction, and obtaining a crude product of the cationic modifier; Step 4: distill the crude cationic modifier under reduced pressure to obtain the cationic modifier.
2. The preparation method according to claim 1, characterized in that In step 1, the secondary amine is one or more of dimethylamine, diethylamine, N-methylethylamine, di-n-propylamine, diisopropylamine, N-methyl-n-propylamine, N-ethyl-n-propylamine, N-methylisopropylamine, and N-ethylisopropylamine; the dichloroalkyl ether is one or more of dichloromethyl ether, dichloroethyl ether, and dichloroisopropyl ether; and the first catalyst is one or more of cuprous chloride, ferric oxide, aluminum oxide, and silicon dioxide.
3. The preparation method according to claim 1, characterized in that: In step 1, the pressure in the reactor is 0-10 kg, and the reaction time is 2-10 h.
4. The preparation method according to claim 1, characterized in that: In step 2, the second catalyst is one or more of sodium sulfate, potassium sulfate, sodium sulfite, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium thiosulfate, potassium thiosulfate, sodium persulfate, and potassium persulfate.
5. The preparation method according to claim 1, characterized in that: In step 2, the dropwise addition time of epichlorohydrin is controlled within 3-10 hours.
6. The preparation method according to claim 1, characterized in that: In step 2, the insulation reaction time is 3-24 hours.
7. The preparation method according to claim 1, characterized in that: In step 4, the temperature of the vacuum distillation is 50-90° C., and the pressure of the vacuum distillation is -0.08 MPa~-0.15 MPa.
8. Use of a cationic modifier obtained by the preparation method according to any one of claims 1 to 7 in dyeing, characterized in that: The steps include: Step S1: padding, using a small padder to perform two dips and two rolls on the cellulose fiber fabric in the modifying liquid; in the modifying liquid, the concentration of the cationic modifier is 3.5% (owf)-7.0% (owf), the concentration of the activator is 1.0% (owf)-2.5% (owf), and the concentration of the penetrant is 3-5g / L; in the two dips and two rolls, the rolling rate of the padder is 70%-80%, and the vehicle speed is 40-50m / min; Step S2: stacking, placing the impregnated cellulose fiber fabric in a plastic film for stacking, the stacking temperature is 25-35° C., and the stacking time is 10-24 hours; Step S3: washing and drying, washing the stacked cellulose fiber fabric to neutrality, and then drying to obtain modified cellulose fiber fabric, the washing temperature is 50-60°C, the drying temperature is 80-90°C, and the drying time is 5-10min; Step S4: putting the modified cellulose fiber fabric into a reactive dye solution, heating it to 60-70° C. for constant temperature dyeing to obtain a dyed fabric, wherein the amount of the reactive dye in the reactive dye solution is 1% (owf)-2% (owf); Step S5: sequentially subjecting the dyed fabric to a first water wash, a soap wash, a second water wash, and drying to obtain a finished fabric.
9. The use according to claim 8, characterized in that In step S5, the temperature of the first water wash and the second water wash are both 85-95°C, the time of the first water wash and the second water wash are both 2-5 minutes, the temperature of the soap wash is 90-95°C, the time of the soap wash is 2-5 minutes, and the amount of soap solution is 1-2g / L.
10. The use according to claim 8, characterized in that Cellulosic fibers include cotton, linen, wool, bamboo, silk and modal.