Four characteristics of amino silicone oil

Amino silicone oil has four important parameters: ammonia value, viscosity, reactivity and particle size. These four parameters basically reflect the quality of the amino silicone oil, and will greatly affect the style of the treated fabric. Such as feel, whiteness, color light and the degree of difficulty of silicone oil emulsification.

1. Ammonia value:

The various properties given by amino silicone oil such as softness, smoothness and fullness are mostly brought by the amino group in the polymer. The amino content can be expressed by the ammonia number, which refers to the number of milliliters of 1 equivalent concentration of hydrochloric acid required to neutralize 1g of amino silicone oil. Therefore, the ammonia value is directly proportional to the molar percentage of the amino content in the silicone oil. The higher the amino content, the higher the ammonia value, the softer and smoother the finish fabric feel, this is because the increase of amino functional groups, the affinity for the fabric is greatly increased, the formation of a more regular molecular arrangement, thus giving the fabric a soft and smooth feel.

However, the active hydrogen in the amino group is easy to oxidize to form chromophore, resulting in yellow or slightly yellow light of the fabric. In the case of the same amino group, obviously with the increase of the amino content (or ammonia value), the probability of oxidation increases, and yellowing is serious.

With the increase of ammonia value, the polarity of amino silicone oil molecules increases, which provides a favorable prerequisite for emulsification of amino silicone oil, and can be made into microemulsions. The selection of emulsifier and the size and distribution of particle size in the emulsion are also related to ammonia value.

2. Viscosity:

The viscosity is related to the molecular weight and molecular weight distribution of the polymer. Generally speaking, the greater the viscosity, the greater the molecular weight of amino silicone oil, the better the film formation on the surface of the fabric, the softer the feel, the better the smoothness, but the worse the permeability, especially for strong twist tight fabrics and fine denier fabrics, amino silicone oil is difficult to penetrate the interior of the fiber, affecting the fabric performance, the viscosity is too large will also make the emulsion stability becomes worse or difficult to make microemulsion. Generally, the product can not be adjusted only by the viscosity, and the performance of the product is often balanced by the ammonia value and viscosity. Usually a low ammonia value requires a high viscosity to balance the softness of the fabric.

Therefore, the smooth feel requires a high viscosity amino modified silicone oil. However, during soft baking, some amino silicone oils cross-link to form films, thereby increasing the molecular weight, so that the initial molecular weight of the amino silicone oil is different from the molecular weight of the amino silicone oil that is eventually formed on the fabric. Therefore, the same amino silicone oil is processed under different process conditions, and the smoothness of the final product can be greatly different. On the other hand, the low viscosity amino silicone oil can also improve the feel of the fabric by adding crosslinking agents or adjusting the baking temperature. Low viscosity amino silicone oil increases the permeability, and then through crosslinking agents and process optimization, the advantages of high and low viscosity amino silicone oil can be combined. Generally, the viscosity of amino silicone oil ranges from 150 to 5000 cm.

However, it is worth noting that the distribution of molecular weight of amino silicone oil may have a greater impact on product performance. The low molecular weight infiltrates into the interior of the fiber, while the high molecular weight is distributed on the outer surface of the fiber, so that the inside and outside of the fiber are wrapped in amino silicone oil, thus giving the fabric a soft and smooth feeling, but the problem may be that the molecular weight difference is too large to affect the stability of the microemulsion.

3. Reactivity:

The reactive amino silicone oil can produce self-crosslinking when finishing, and the improvement of the cross-linking degree will increase the smoothness, softness and fullness of the fabric, especially the improvement of elasticity. Of course, the general amino silicone oil can also increase the degree of crosslinking when using crosslinking agents or increasing the baking conditions, and thus can also improve the rebound. Hydroxyl or methyl amino terminal amino silicone oil, the higher the ammonia value, the better the crosslinking degree, the better the elasticity.

4.microemulsion particle size and emulsion charge:

The particle size of the amino silicone oil emulsion is small, generally less than 0.15μ, so the emulsion is com

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