Sodium tripolyphosphate is the most widely used dispersing agent during the 20th century. It is very effective, and has been one of the main adjuvants in the manufacture of detergents. In addition to being a dispersing agent, it is a water hardness sequestrant, an emulsifier and a stabiliser. However, the massive use of phosphates has had a serious environmental impact, and their use has been limited.
Nowadays, environmental care is a major factor in detergent formulation, and the substitution of phosphates, which are responsible for eutrophication, has been a maxim in recent decades.
The reduction in phosphorus content means a loss of efficacy in detergents with conventional formulations, and the home care industry must look for new options with alternative ingredients capable of performing such important functions as dispersion.
What is a dispersing agent used for?
A dispersing agent is a substance that is added to a formulation to ease the suspension of solid particles in a liquid medium, such as a colloidal suspension or an emulsion, so as to promote phase separation and to avoid sedimentation, precipitation or agglutination.
Dispersing agents are used in many industrial applications
Dispersing agents are used as anti-redeposition, scale inhibitors and bulk density modification in applications such as laundry detergent, printing ink, ceramics, water treatment or agricultural products. Detergent manufacture is also one of the industrial applications of dispersing agents.
Acrylic dispersing agents for detergents
Detergents must be able to disperse different types of materials within the washing liquid. In a detergent, a dispersing agent has the task of keeping the dirt in suspension, and preventing it from being redeposited on the substrates or surfaces to be cleaned.
Acrylic dispersing agents
Acrylic dispersing agents have been incorporated into formulations as a partial substitution for the various phosphates commonly found in detergents. They are acrylic and acrylic-maleic polymers designed to improve the properties of household, industrial and institutional detergents.
These polymers protect surfactants and other components against inactivation by ions, prevent redeposition of dirt and scale and keep washing machines in better conditions.
Which dispersing agent to use in a detergent?
Depending on the detergent application, the manufacturing process or the desired performance properties, acrylic dispersing agents are selected from a wide range of products.
Water-soluble homopolymers of acrylic acid are very effective dispersing agents, especially in phosphate-free laundry detergents. The high dispersing effect of these polymers is useful in preventing the deposition of solids on various fabrics.
Water-soluble homopolymers of acrylic acid are also used in dishwashing formulations, industrial detergents and in water treatment plants. In these applications they inhibit limescale build-up and disperse poorly soluble salts.
Water-soluble copolymers of acrylic acid and maleic acid (acrylic-maleic copolymers) prevent the redeposition of dirt on fabrics and of limescale inside the washing machine. This results in the prevention of stiffening and solidifying of fabrics due to limescale build-up and prolongs the life of the washing machines.
Acrylic-maleic copolymers prevent fabrics from getting stiff due to incrustations. They also prevent the redeposition of dirt on the fabric and limescale inside the washing machine.
It is possible to formulate industrial laundry detergents based on acrylic-maleic copolymers together with sodium hydroxide and other sequestrants.
There are also other types of speciality acrylic-based polymers with multiple functionalities related to the secondary efficiency of detergents and the reduction of production costs.
Benefits of dispersing agents
Acrylic dispersing agents compensate for the loss of performance in phosphate-free detergents. They are also useful to economize on manufacturing and to solve the flowability problems of powder detergents.
Redeposition of dirt, transfer of dyes, appearance of fabric stiffness or limescale build-up are indications of poor detergent performance which can be solved by the addition of appropriate dispersing agents.
Formulations with acrylic dispersing agents:
- Have better detergent properties.
- Reduce redeposition of dirt.
- Minimise calcium salt incrustations on fabrics and surfaces.
- Prevent limescale build-up on equipment.
- Minimise spotting and filming on glass in dishwasher applications.
- Allow surfaces to dry faster.
- Improve the deficiencies of phosphorus-free formulas.
- Allow to reduce ingredient costs and production costs.
In Quimidroga’s Cosmetics catalogue there are multiple dispersion and sequestering solutions to formulate detergents with optimum performance. At Quimidroga’s laboratory, these ingredients are characterised and formulations are developed to achieve combinations with the maximum benefits for each application.