Technical control: [Printing and dyeing learning and exchange] dry recommended, many partners have used silicone oil, in the finishing time, do feel is to use this, but, what is silicone oil? Why add a silicone oil fabric feel becomes better? I’m afraid that many partners are still confused about this issue.
First, let’s talk about silicone oil
Silicone oil usually refers to the linear polysiloxane products that remain liquid at room temperature, generally colorless (or light yellow), odorless, non-toxic, non-volatile liquid. They all have a low molecular weight and are in a fluid state at room temperature, so they are usually also called silicone oils. It is generally not used solely, but made by special formulation, often as an auxiliary material to produce some kind of effect.
Generally speaking, there are 3 basic forms of silicone oil on the market: pure silicone oil, solution, and emulsion.
1
Pure silicone fluids are very stable
Heat resistance, frost resistance, good storability, high flash point and high ignition point, few storage and transportation problems.
2
In practice it is often necessary to dilute silicone oil solutions
Sometimes it is desired to add active auxiliary agents (catalysts, cross-linking agents, etc.) to the solution in order to facilitate storage and use, aliphatic, aromatic or chlorinated hydrocarbons can be used as solvents as needed, and other types of solvents are used only under special circumstances, and the general polymer polysiloxane solution, the concentration can only be up to 35%, otherwise the viscosity is too large.
3
A large proportion of silicone oil or products containing silicone oil is made into emulsion form
It has the advantages of being inexpensive, not easy to burn, and not harmful to health when compared with solvent silicone oil. Unlike solvent-based, all silicone emulsions are “oil-in-water” non-homogeneous systems, where the external closed phase is aqueous and the silicone oil is dispersed in the aqueous phase in very fine droplets that can be easily diluted with water to the required concentration for application.
The role of silicone oils in the textile industry
Silicone oil is used in the textile and apparel industry as a fabric softener, lubricant, water repellent, finishing agent, etc. To meet the high-end needs of textiles, chemical manufacturers are also developing silicone oils that can be used in the same bath as various functional additives such as water repellents, flame retardants, antistatic agents, and color fixing agents, and that have a good feel. In addition, in order to improve the performance of fabrics, there are silicone products that can be used in the same bath with dyeing, silicone oil for cotton that has a cool feeling, silicone products that can improve the feel of fabrics, and silicone deepening agents that give fabrics excellent deepening effects, good storage stability, do not affect color fastness, and have a good feel.
In addition to the functionalization of textiles as additives in textiles, silicone products will also be used in other areas of textiles, such as the combination of silicone and polyurethane to form the coating of fabrics; silicone and acrylic polymerization to form the printing of fabrics; silicone and organic fluorine combination to form a waterproof coating on the surface of fabrics, etc.
Silicone oil can be divided into primary products and secondary products according to its processing status.
The former refers to the pre-processing silicone oil products, including hydroxy silicone oil, silicon-functional silicone oil, carbon-functional silicone oil and non-active modified silicone oil 4 major categories. Among these four categories, it is customary to call the first two categories as linear silicone oil and the last two categories as modified silicone oil.
Secondary silicone oil products refer to silicone oil as raw materials, with thickeners, surfactants, solvents and additives, and processed by a specific process into grease paste, emulsion and solution products, such as silicone grease, silicone paste, defoamer, release agent and isolation agent, etc..
The evolution of domestic silicone softener history
The production and application of silicone softeners in China can be said to have gone through four generations.
The first generation
Is the end of hydroxyl high molecular weight polysiloxane emulsion (hydroxymilk) from octamethylcyclotetrasiloxane (D4), water, emulsifiers, catalysts and other raw materials in certain conditions emulsion polymerization.
Second generation
Polyether-modified silicone oil is made by the silicon-hydrogen addition reaction between methyl hydrogen-containing silicone oil and polyethers such as polyethylene glycol and polypropylene glycol with unsaturated bonds at the end.
The third generation
It is a polysiloxane emulsion with active groups (amino and epoxy groups) polymerization method is basically the same as hydroxyl emulsion, the difference is that a certain amount of silane coupling agent is added to the raw material. The introduction of these amino and epoxy functional groups greatly improves the softness, smoothness, elasticity and durability of the finishing effect of the fabric after finishing, but the disadvantage is that there is a broken emulsion, oil bleaching phenomenon in the use process. These polysiloxane emulsions with reactive groups are strongly cationic or anionic due to the use of ionic surfactants, and are more selective and less compatible with other additives.
Fourth generation
Is represented by amino silicone oil modified silicone oil is currently the most representative silicone softener varieties on the market, we usually call the ammonia ethyl aminopropyl polydimethylsiloxane standard amino silicone oil, and the other ammonia substituted polysiloxane called modified amino silicone oil. Amino silicone oil due to the strong polarity of the amino group, and the fiber surface of the hydroxyl group, carboxyl groups and other interactions with the fiber to form a very strong orientation, adsorption, so that the coefficient of friction between the fibers decreased, which means that when the fabric is held in the hands, with a very small force can make the fibers begin to slide between them, so as to feel soft. In recent years, organic modified silicone oil has been developed rapidly, and many organic modified silicone oils with special properties have appeared.
