Since the softener can give the fabric a soft and comfortable feel, it can improve the quality and added value of the fabric. This is in line with the current trend of pursuing high-end and comfortable clothing. Increasing the amount of softeners, which also promoted the rapid development of softener varieties. There are hundreds of domestic softener varieties, which are described as follows:
1. Anionic softener: In addition to soap, sulfonated oil, etc., the main components of the anionic softener are stearyl succinate sodium sulfonate, stearyl ester sulfate and other anti-ion compounds with long chain alkanes or Anionic and non-ionic compounds. Generally, it has good wettability and thermal stability, can be used in the same bath with fluorescent whitening agent, and can be used as a softener for extra-white fabrics. It is also more suitable for cellulosic fibers, which can give fabrics better water absorption, but its adsorption to fibers is similar to that of direct dyes, which is relatively weak, so the softening effect is poor, and it is easy to be washed away. In addition, because it has a softening effect in the bath, it can be used for silk scouring to prevent scratches (grey scratches).
2. Non-ionic softener: Non-ionic softener is generally polyoxyethylene ester (or ether) of decaacid (or alcohol), pentaerythritol or fatty ester of sorbitol. Since non-ionic softeners have poorer absorption to fibers than ionic softeners, they can only play a smoothing effect. However, it can be used in combination with ionic softeners. It has good compatibility with other electrolytes, and has no disadvantages of yellowing the fabric. It can be used as a non-durable soft finishing agent, and can also be used as a synthetic fiber spinning oil. An important part of the agent. Some of its products can be used as silk-like finishing agents for fabric "Siming Yin".
3. Cationic softener: There are many varieties of this kind of softener, and it is currently the most commonly used softener. Mainly because most fibers are negatively charged in water, cationic softeners are easily adsorbed on the surface of the fibers, have strong binding ability, can withstand high temperatures and washes, and the fabrics are plump and smooth after finishing, which can improve the wear resistance and wear resistance of the fabrics. It has a strong tearing force and has a certain antistatic effect on synthetic fibers. Therefore, it is widely used in cotton, nylon, acrylic and other fabrics, and this variety is also suitable for silk. However, some cationic softeners are prone to yellowing at high temperatures, accompanied by a decrease in light fastness. The cationic softener is generally a derivative of octadecylamine or dimethyloctadecylamine or a condensate of stearic acid and polyvinyl polyamine. According to its structure, it can be divided into tertiary amine softener, quaternary ammonium softener, imidazoline quaternary ammonium softener, dialkyl dimethyl quaternary ammonium softener and so on.
4. Amphoteric softener: Amphoteric softener is a type of softener developed to improve cationic softeners. It has a strong affinity for synthetic fibers, and has no disadvantages such as yellowing and discoloration of dyes. It can also be used in the re-training process of silk to make the silk feel better. Amphoteric softeners can also be used together with cationic softeners to play a synergistic effect. Such softeners are generally of alkylamine lactone type structure.
5. Silicone softener: This kind of softener is emulsion or microemulsion of polysiloxane and its derivatives, which can make the fabric have a good soft and smooth hand feeling. The products include emulsion polymerization, polymer silicone oil emulsification, modification, compounding and other production techniques, which have basically formed a system and supply more varieties and brands. But the application effect and performance are still very different.
Dimethyl silicone emulsion: This is the first product used in silicone softeners. The relative molecular mass of silicone oil used as a softener is generally 60,000-70,000. After finishing, it can give the fabric a slippery, firm and cool hand, reduce the friction coefficient of the fabric, and improve the abrasion resistance and seamability of the fabric. However, because there are no reactive groups on the molecular chain, it cannot react with the fiber or cross-link by itself, but only rely on molecules to attract and attach to the surface of the fiber, so it has poor washing durability and limited improvement in elasticity.
Silicone Hydroxy Emulsion (Hydroxy Silicone Oil Emulsion): This is the most widely used silicone softener in my country in the 1980s. Its relative molecular mass is generally 60,000-80,000. The larger the relative molecular mass, the better the softness and smoothness. Because of its molecular chain end and Hong group end-capped, under the action of crosslinking agent and catalyst, it can crosslink with the reactive base of the fiber or itself to form a certain elastic polymer film, so it is washable. , And can improve the elasticity of the fabric. According to the ionicity of the emulsifier used, organosilicone hydroxyemulsion is divided into cationic silicone hydroxyemulsion and anionic silicone hydroxyemulsion. Although the presence of hydroxyl groups at the end of the molecular chain of silicone hydroxyemulsion is helpful to improve its hydrophilicity and emulsion stability, it is difficult to control the fineness and uniformity of the emulsion particles of silicone hydroxyemulsion, so the stability of the emulsion is also very good. It is difficult to master, and it is easy to cause oil bleaching during application, which makes it difficult to remove oil spots and other defects on the fabric. Therefore, the emulsion stability of the silicone hydroxyemulsion softener is also an important indicator for evaluating its quality.
Hydrophilic soluble silicone (polyether hydrophilic silicone): This type of silicone softener is usually polyether and epoxy-modified polysiloxane. The appearance is a colorless and transparent thick liquid, which can give fabrics Good moisture absorption, air permeability and antistatic properties. Due to its non-ionic properties, it can be mixed with various additives. When it is used together with resin, it can reduce the resin's chlorine absorption and release formaldehyde; in addition to resin finishing and soft finishing, it is also widely used in paint dyeing process, not only can improve the hand feeling of fabrics affected by adhesives, The shortcomings of the adhesive roller can also be improved.
Amino-modified silicone: The introduction of amino groups into the macromolecular chain of polysiloxane can greatly improve the performance of silicone. The introduction of amino groups can not only form firm orientation and adsorption with fibers, reduce the friction coefficient between fibers, but also chemically react with epoxy groups, carboxyl groups, and hydroxyl groups, so it can be applied to cotton, wool, silk, and viscose. Fiber, polyester, nylon, acrylic and other fibers and their blended fabrics. After finishing the fabric, it can obtain excellent softness and resilience, and its hand feel is soft and plump, smooth and delicate. Generally speaking, the higher the amino content, the better the softness. But higher amino content also means greater yellowing. This is mainly because the side chain—(CH2)NH(CH2)2NH2 has two amine groups (primary amine group and secondary amine group), a total of three active hydrogen atoms, easy to oxidize to form a chromophore, and this double The amine structure has the synergistic effect of accelerating oxidation. Therefore, there must be an optimal balance between amino content and yellowing.
The amino-modified silicone is made into microemulsion, which has developed rapidly in the past ten years. Since the amino group is introduced into the siloxane molecule to improve its hydrophilicity, the appropriate emulsifier and preparation process can be selected to make it into a microemulsion with a particle size of less than 0.15 μm. Since its particle size is smaller than the wavelength of visible light, it has no resistance to visible light, so it can make the emulsion transparent. The particle size of its particles is only 1/10 of the particle size of ordinary emulsions, which increases the number of effective particles in the microemulsion by 103 times (if the concentration is the same), and the chance of contact between the microemulsion and the fabric is greatly increased. The surface has good spreadability and easily penetrates into the fiber. Therefore, this product can impart good internal softness to the fabric, and this softness is also more durable. The water solubility, storage stability, heat stability, and shear stability of microemulsion products are generally better.
Although the commonly used bisamino silicone softener has good softening effect, its whiteness, water absorption, and easy decontamination are all poor, and it becomes serious with the increase of amino functional groups in the polymer. In order to improve these shortcomings, it can be achieved by changing the type and number of amino functional groups. Changing the type of amino functional group is mainly to change the primary amino group into a secondary or tertiary amino group, such as N-propylcyclohexylamine (secondary amine) and N-propylpiperazine (tertiary amine) modified silicone softener It has been developed for textile finishing. This kind of softener can reduce yellowing during baking, and has less hydrophobicity than the silicone softener with primary amine functional group, but it makes the texture of the fabric a little boring. Mainly used for soft finishing of bleached woven and light-colored fabrics.
In addition, in order to obtain an ultra-smooth feel, the two ends of the dimethylsiloxane macromolecule are terminated with amino modification, which can form a very neat directional arrangement on the fabric, thereby obtaining an excellent smooth feel; Part of the side chain groups and both ends of the siloxane are substituted with amino modification. Use it as a finishing agent for fabrics, which can make the fabrics more flexible. Silicone softeners are now developing rapidly, with more and more varieties, and their prices have fallen. The number of applications using silicone softeners has increased significantly. In addition to the various types of silicone softeners mentioned above, there are also silicone softeners such as epoxy modification, amide modification, and carboxyl modification. Because there should be less at present, I won't introduce them here.
6. Low-molecular-weight polyethylene emulsion: The softener is a product of low-molecular-weight polyethylene after being oxidized and then emulsified. It has a certain affinity to the fiber, makes the object have a smooth feel, can be used in the same bath with the resin, and can improve the tearing strength and wear resistance reduced by the resin finishing. It is a cheap silicone softener before the popularization and application. Fabric soft and smooth additive. At present, this kind of softener is generally not used alone, and can be used as a compound component of various softeners, and can also be used as a stabilizer in hydroxy silicone emulsion.