Magnesium aluminosilicate
Basic Information
Product name: dialuminum, magnesium, dihydroxy(oxo)silane, hydrate
Alias: Almasilato; Simagel; Almasilate; Dianeusine; Almasilatum [INN-Latin];
CAS number: 71205-22-6
Molecular formula: Al2MgO8Si2
Molecular weight: 262.43400
Exact Mass: 261.86100
PSA: 73.84000 [1]
Uses
As a stabilizer, suspending agent and thickener, it is used in personal care (such as toothpaste), cosmetics, medicine, pesticides, polishing agents, lubricants, coatings, paints, lithium batteries, engineering plastics and other fields. The product is in the form of small white flakes or powder, and the finest particle size can reach -325 mesh. Tasteless and odorless. Generally, the loss on drying can be controlled below 7.5%, and the loss on ignition is below 15%. It can swell into a colloidal dispersion in water, which is slightly alkaline. The colloid is stable at pH 3.5 to 11. The usual dosage is 0.5% to 2.5%, and the maximum dosage is 5%. The viscosity range of 5% water dispersion is 50~700CPS, and some can reach thousands of CPS.
Magnesium aluminum silicate (disintegrant) has a unique three-dimensional chain structure and special needle and rod-shaped crystal structure, so it has unusual colloidal and adsorption properties. It is widely used in paint and coating industry for its excellent thickening, suspending and colloidal shaking and melting properties. Formation of "card palace" associative network structure in aqueous medium
Advantages
(1) It is a good emulsion stabilizer
Magnesium aluminum silicate is a stabilizer for oil-in-water and water-in-oil emulsions, and its outstanding advantage is that it can stabilize oil-in-water emulsions at low concentrations. At elevated temperatures, the tendency of the emulsion to thin out or be destroyed is reduced. It has protective colloid activity, strong hydrophilic properties and the ability to thicken the outer phase of the emulsion. A small amount of magnesium aluminum silicate (less than 1%) can stabilize various oils (mineral oils, vegetable oils) and emulsions containing anionic or nonionic surfactants. It also provides spreadability, increased viscosity and film-forming properties. It can be used in hand cream, shaving cream, deodorant lotion, toothpaste, shampoo cream and many other similar products.
(2) It is an excellent suspending agent
Since magnesium aluminum silicate is thixotropic, it can protect the colloid, so:
1. It can prevent suspended matter products from hardening.
2. Can control moisture. Suspensions are easily redispersed when they have a tendency to settle.
3. The product can obtain a uniform dose.
4. The maximum suspension can be obtained without impairing the pourability of the product.
5. It does not form irreversible gels like many organic glues.
6. Under the same viscosity, it has more suspending effect than organic glue, especially at low viscosity, because it has good thixotropy.
7. Its water dispersion can suspend a wide variety of powdery substances, including pigments, resins, friction agents, talc, clay, titanium dioxide, colloidal sulfur, aluminum hydroxide , barium salts, iron oxides, and smithsonite.
(3) It can improve the effectiveness of organic glue
The combination of organic glue and magnesium aluminum silicate can exert the best characteristics of both.
1. It can improve the suspension and make the final product easy to redisperse. For example, in hair removal Liu, magnesium aluminum silicate and methyl cellulose are combined to obtain a smooth and uniform dispersion; in acne cream and lotion, magnesium aluminum silicate Mixed with methyl cellulose, it can reduce the precipitation of water and the precipitation of powder.
2. Since it can reduce tackiness and blocking, it can improve the feel and consistency of the organic glue solution. Especially for toothpaste, obviously.
3. Mixing with organic glue can improve the spreadability and structure of the dispersion, and can play an important role in pigmented cosmetics.
(4) It is a non-moving adhesive
Magnesium aluminum silicate, unlike other organic binders, does not migrate to the surface of the tablet or rod during drying. This non-migrating property is necessary to ensure uniform color, hardness and wipe-off properties of the product. And in rod, briquette and tablet formulations, magnesium aluminum silicate can be used to control the hardness and wiping off of the product, and it can also be used to bond different powders, such as talc, pigments and pharmaceuticals.
(5) It is a disintegrant for tablets
Magnesium aluminum silicate is a stable small bulk disintegrant in tablets. When disintegration properties need to be balanced against hardness, it can be used to combine product properties, especially effective in bulk tablets where the active ingredient is the predominant weight and volume, and it is also effective in sandwich tablets. Therefore, the volume should be as small as possible in manufacturing. In the tablet forming process, adding 2~5% dry magnesium aluminum silicate can get the best disintegration degree. In a granulation study of calcium sulfate in 5% ethylcellulose in ethanol, magnesium aluminum silicate provides faster disintegration than starch. In the tablet containing 1.5% magnesium aluminum silicate, its disintegration is twice as fast as that containing the same amount of corn starch. With 1.5% magnesium aluminum silicate F, the disintegration rate is less than 5 minutes.
(6) It is a viscosity modifier and thickener
As viscosity modifiers and thickeners, magnesium aluminum silicates are very effective in controlling the consistency of emulsions and suspensions. It imparts shaping and dispersing properties to creams and liquids and a cosmetic beauty. It is a hydrophilic colloid and has pseudoplastic flow properties. Therefore, when some creams, liquids, pastes and aerosol products need to be reformulated for new packaging, their viscosity can be adjusted with magnesium aluminum silicate.
(7) Superior performance than organic colloids
1. Magnesium-aluminum silicate particles are uniform, without any grit for medicinal and cosmetic specifications.
2. The dispersion is non-sticky and non-greasy.
3. It is also stable for long-term storage in general containers, unlike organic colloids that are decomposed by bacteria.
4. Can spread immediately in water without soaking. Both high shear and low shear mixers can be used to prepare its aqueous dispersion, as can hot and cold water.
5. Suspended powders and pigments more effectively than organic gums at lower viscosity.
6. In many cases, free-flowing suspensions can be provided, while organocolloids form irreversible colloids or agglomerates.
(8) Non-toxic and non-irritating
The U.S. Food and Drug Administration (FDA) has confirmed that Silica is safe as a food additive and has never banned its use in oral medicines. The safe use of magnesium aluminum silicate has a long history, and has undergone numerous irritation and chronic toxicity tests to test its safety in pharmaceuticals and cosmetics. In 1968, acute eye and skin toxicity studies were conducted, reconfirming it to be non-irritating and non-toxic.
(9) Can absorb certain organic substances Magnesium aluminum silicate can absorb certain pigments, enzyme preparations, flavors or food flavors, and can expand the Uses of flavor concentrates, reduce the bitterness of some drugs and enhance the flavor. It can also react with some drugs, improving their Uses.
(10) Has alkali exchange ability
Magnesium-aluminum silicate reacts with cationic fatty amines and quaternary iron compounds, and a similar ion-exchange reaction has been used to produce neutral magnesium-aluminum silicates. Some swelling capacity in water is attenuated, but can be made into an aqueous dispersion. Neutral magnesium aluminum silicate is especially suitable for some pharmaceutical suspensions
