New Material: Sharing Practical Experience, Research On Cationic Modifier

Recently, relevant textile science and technology studios have been studying the application of cationic modification in the textile industry for more than ten years, and have not stopped until now. At the same time, they have openly shared practical experience with the industry, hoping that everyone can make further progress in the environmental protection textile industry and contribute to the industry. 

Principle of cationic modifier:

It is to improve the adsorption capacity and adhesion of compounds in specific media by introducing groups that can be positively charged. This modifier usually refers to a special cationic polymer, which can make the fiber become cationic after reacting with the cellulose fiber, thus significantly

Improve the dye uptake of reactive and direct dyes on the fiber.

The main applications of cationic modifiers include cotton fabric treatment. By changing the surface charge property of the fiber, the adsorption and diffusion of dyes on the fiber can be improved, and then the dyeing effect and fastness can be improved.

The action mechanism of cationic modifier involves fiber banding in dye solution

Electricity.

Under neutral or alkaline conditions, the fiber surface is generally negatively charged, which is caused by the ionization of carboxyl groups, sulfonic groups, etc. in the fiber or carboxyl groups generated by fiber oxidation, and the absorption of negatively charged particles such as OH - in the dye solution.

Since most dyes used for dyeing cellulose fibers (such as reactive dyes, direct dyes, vat dyes leucosomes, etc.) also have negative charges in the dyeing bath, there is electrostatic repulsion force during dyeing, which causes the dye uptake to be hindered and the dye uptake to be reduced. Cationic modification

By changing the charge property of the fiber surface, the agent can reduce the electrostatic repulsion between the dye and the fiber, thus improving the dye uptake and dyeing quality.

Application of cationic modifier:

Because the fabric is often negatively charged, it repels negatively charged latex particles, so the use of cationic emulsifiers can overcome this obstacle and improve the impregnation effect. Cationic modifier is not only used in textile industry, but also widely used in printing and dyeing, paper making and coating

Materials, printing ink, cosmetics, daily necessities, medicine and other fields, with their good dispersion, stability, sterilization, softness and other characteristics, play an important role in many industries.

In addition, the application of cationic modifiers also includes the preparation of positively charged polymer emulsions, which can be used to impregnate fabrics.

Cationic modifiers are widely used. For example, in the textile industry, they can improve the handle of paint dyed fabrics, reduce or eliminate the use of adhesives, and maintain good color fastness. In addition, cationic modifiers are also used in salt free dyeing with reactive dyes

It plays a key role in improving the adsorption capacity and diffusion of cationic agent on cotton fibers by introducing negative charges to cotton fabrics, thus greatly reducing the consumption of chemicals and dyeing costs. ‌

Composition of cationic modifier:

The components of cationic modifiers mainly include cationic quaternary amine salt polymers, alcohols, aliphatic compounds, aromatic compounds, nitrogen-containing compounds and phosphorus containing compounds. These ingredients form cationic modifiers through specific reaction, treatment and extraction processes

Its ionic property is cation and can be dissolved in water.

Raw material source of cationic modifier

The main raw materials are from petrochemical industry and chemical production industry. It mainly includes the following categories:

1. Alcohols: such as methanol, ethanol, propanol, etc.

2. Aliphatic compounds: such as stearic acid, fatty alcohol, etc.

3. Aromatic compounds: such as styrene, styrene propylene, etc.

4. Nitrogenous compounds: such as ethylene propylene amine, ethylene pyrrolidine, etc.

5. Phosphorous compounds: such as dibutyl phosphate, methyl phosphate, etc.

These raw materials are added with different reagents and catalysts, and after multiple reactions, treatment, purification and other processes, cationic modifiers are prepared. Their properties vary with different raw materials.

Use method of cationic modifier:

The use method of cationic modifier mainly includes the following steps:

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Pretreatment process of modification:

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First, add cold water into the dyeing machine, then add penetrant, and put the garment into the machine for wetting treatment for 5 minutes.

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Then, add cationic modifier and treat for 10 minutes. ‌

Add soda ash and treat for 10 minutes to adjust the pH value of the dye bath to 10-11. ‌

Gradually raise the temperature to 65-80 ℃ and treat for 30 minutes. ‌

Finally, drain water and clean it twice with cold water. ‌

Dyeing process prescription:

Add cold water into the dyeing machine, then add leveling agent O, and treat for 10 minutes.

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Add paint paste and treat for 10 minutes. ‌

Gradually raise the temperature to 75-80 ℃ and treat for 30 minutes. ‌

Drain and clean twice with cold water. ‌

If the requirements for fastness are high, the adhesive can be added for color fixation after the paint is dyed. The amount of adhesive is generally 6-8% (o.w.f)

Treatment at ℃ for 10 minutes, then water washing.

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matters needing attention:

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The modifier has good affinity to cellulose fiber. In order to make the fabric modified evenly, the modifier should be added slowly. ‌

Soda ash makes the modifier chemically bond with the fiber. To make the reaction sufficient, the reaction temperature and time should be well controlled.

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In pigment dyeing, medium and light colors can be washed without binder and enzyme, and certain effects of old washing and whitening can also be obtained by soaping only at low temperature.

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Storage: sealed storage, with a storage period of 12 months and 12 months under normal temperature. ‌

Cationic modifier type:

Cationic modifier type; It mainly includes quaternary ammonium salts, fatty amines, ureas and acetals.

The details are as follows:

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　　. Quaternary ammonium salt: it is the most widely used cationic modifier, which is composed of one long chain carbon group and three or four quaternary ammonium salt groups. It has good dispersion, stability, sterilization, softness and other characteristics, and is widely used in textile, printing and dyeing, paper, paint, ink

And other fields.

2. Fatty amine: It is composed of a long-chain carbon group and functional groups such as NH2, NH (CH2) nNH2, etc. It has certain hydrophilicity and the performance of promoting the dispersion of colorants, and is mainly used in printing and dyeing, textile, paper making, leather and other fields.

　　3.

Ureas: can be regarded as the conversion products of quaternary ammonium salts and aliphatic amines. They have the characteristics of low foam, medium gel cationic surfactant and good ion association ability, and are commonly used in textile, printing and dyeing, paper making, softener and other fields.

4. Acetals: They are synthesized by acetal reaction and usually have good redispersibility, anti adhesion and softness, and are suitable for textile printing and dyeing, leather making, softener and other fields.

These cationic modifiers are widely used to improve the performance and stability of products due to their different characteristics and application fields.

Cationic modifier formula:

Cationic modifier formula:

The formula of cationic modifier can be prepared by different methods, and the details are as follows:

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Synthesis method 1: the main raw materials are epichlorohydrin, dimethylamine and diethylenetriamine, and the optimal synthesis process is n (epichlorohydrin) ∶ n (dimethylamine) ∶ n (diethylenetriamine)=1.0 ∶ 1.0 ∶ 0.10. After the dropping temperature is controlled at 20~30 ℃, slowly raise the temperature to 70

℃ and heat preservation for 5 hours.

2. Synthesis method 2: use polyethylene citrate diamide, sorbitol bicarbonate sodium salt complex to cross link with polyethylene propylene carboxylamide, and use cationic surfactant to modify the cross-linked product. In addition, it can also be

The ethylene glycol ester reacts with the aqueous solution of diethylenetriamine to obtain polyethylene phthalate (diethylenetriamine ester) salt, which reacts with polyvinyl alcohol and adds a cationic polar solvent.

These methods provide different ways to prepare cationic modifiers, which are suitable for different application scenarios and needs.

PH value of cationic modifier:

PH value of cationic modifier Varies by product and application. ‌

In some descriptions, the pH of the cationic modifier is mentioned as 5.0 ± 1.0 (1% aqueous solution).

In another application, it is mentioned that the modifier can be used under acidic conditions (pH: 4-5) and alkaline conditions (pH: 9-11).

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Another study discussed the optimal process conditions of the cationic modifier PAE resin, including the modified pH value of 9~10.

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In addition, in a description of paint dyeing crosslinking agent (cationic modifier), the pH value is mentioned as 7-7.5 (1% cq).

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These information show that the pH value of cationic modifier is wide, and the specific value depends on the product characteristics and application needs. In practical application, it is very important to select the appropriate pH value to achieve the best modification effect.

Preparation method of cationic modifier:

The preparation and synthesis methods of cationic modifiers mainly include the following:

1. Preparation of efficient cationic modifier for cotton fabric: this method involves reacting urea, glyoxal and formaldehyde to obtain 2D resin solution, and then dropping the monomer mixture of dimethyldiallylammonium chloride and hydroxyacrylate compounds and initiator water-soluble into the reactor

Liquid to obtain polymer solution.

Finally, 2D resin solution and polymer solution are mixed, and the pH is adjusted after vacuum distillation for etherification reaction, and then cooled to room temperature to obtain an efficient cationic modifier for cotton fabric.

This method is simple and easy to operate. The cationic modifier prepared can improve the adsorption performance of cotton fabric dyes, have a good dyeing effect, reduce the pollution of dye solution to water bodies, and is conducive to the ecological protection of water bodies.

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Synthesis of cationic modifier: the cationic modifier is synthesized with epichlorohydrin, dimethylamine and diethylenetriamine as the main raw materials by controlling the proportion and amount of reactants, reaction temperature and reaction time. ‌

The optimal synthesis process is: n (epichlorohydrin) n (dimethylamine) n (diethylenetriamine)=1.01.00.10, the dropping temperature is controlled at 20~30 ℃, and then slowly heated to 70 ℃ for 5 hours.

After being treated with cationic modifier, cotton fabrics can be dyed with reactive dyes without salt, which can reach the color depth value (K/S value) of conventional dyed fabrics, reduce the amount of dyes and soda ash and shorten the dyeing time. ‌

3. Preparation of double reactive active group and double cation base cationic modifier: This method involves reacting raw materials containing specific compounds to prepare a cationic modifier with double reactive active group and double cation base. Specific preparation methods include specific chemical reactions

The step is to provide a cationic modifier with specific performance.

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These methods have their own characteristics, aiming at preparing cationic modifiers suitable for different application scenarios through different raw materials and process conditions, so as to improve the dyeing performance, durability and environmental protection of cotton fabrics or other fiber materials. ‌