Seeking Options for Formulation pH Control for Laundry Liquid Formulations

• A Technology
• A Material

Need a buffer for concentrated liquid detergents that controls the pH between 6 - 8 during manufacture. The buffer must be compatible with concentrated liquid detergents and ideally would have a low ionic strength and be non-amine containing.

Control of the pH of concentrated Laundry liquid detergents during the manufacturing process and subsequently during the wash process is critical. Current buffers utilised either do not fully control the pH within the desired pH range, or can cause additional instabilities within the formulation.

Therefore, there is a need to identify alternative buffers for concentrated liquid detergents that are compatible with the formulation and can effectively control the pH during manufacture between 6 -8. Ideally the buffer would be highly effective at maintaining pH in this range to addition of significant levels of both acid and alkali based materials (typically +/- 10% of the acidic and alkali raw materials used within the formulation).

We are also interested in materials that can provide efficient buffering within part of this range (eg. pH 6-7; 7-8 etc) and ideally would have a low ionic strength and be non-amine containing.

Buffer materials are required to control both the formulation and in-wash pH of laundry liquids. During the manufacturing process of concentrated laundry liquid detergents it is essential to control the pH of the formulation to both over-dosing and under-dosing of acidic and alkali materials (for example, neutralisation of surfactant within the formulation). Poor control of pH would result in liquid detergents with either too high or too low pH which can cause both physical and chemical instability of ingredients within the formulation.

Conventional buffers with high levels of charge can cause unwanted changes to surfactant phase behaviour which can induce compositional instability. Conventional amine based buffering chemistries are known to us and we are now seeking alternative materials.

Previously assessed buffers include the following:

• Triethanol amine (TEA)
• Monoethanol aminde (MEA)
• Citric acid
• Fatty acid
• Imidazole and derivatives
• PIPES (1,4 piperazinediethanesulphonic acid)
• MES (2-(N-morpholino)propane sulphonic acid)
• ADA (N-(2 acetamido)-2 iminodiacetic acid)
• ACES (N-(2-acetamido-2 aminoethane sulphonic acid)
• MOPSO (beta-hydroxy-4-morpholinepropane sulphonic acid)
• Bis-tris propane (1,3-Bis[tris(hydroxylmethyl)methylamino]propane
• BES (N,N-Bis (2-hydroxyethyl)-2 aminoethanesulphonic acid)
• MOPS 3-(N-morpholino)propane sulphonic acid
• HEPES 4-(2-hydroxymethyl)-2,2’,2’’ nitriloethanol
• And similar known buffers

These buffers either are not readily compatible with a concentrated liquid detergent formulation (either induce physical or chemical instability) or do not have the required buffering window.

Minimum expectations:

Solution must show good buffer control under defined pH range (i.e. Buffer plateau region in pH target of interest). An ideal pH titration profile would be:

However, we are also interested in buffers that exhibit a long, shallow buffer plateaux region at narrower pH window (eg pH 6-7). It is essential that buffering capacity could withstand variations in acid/alkali materials concentration associated to normal processing/manufacturing tolerances for liquid detergents (i.e., +/- 10%).

An example of a pH titration curve that is not acceptable would be:

The buffer should preferably contain a low level of charge (ideally charge neutral). As a minimum must not induce phase separation of the liquid detergent. The buffer also is preferably non-amine containing.

• Buffers from Food Industry?
• Zwitterionic surfactants?
• Microbiology media manufacturers?
• Blood (storage) buffers?

• Materials already assessed as defined previously (including other amine-containing buffers)
• Materials that are not available on multi-tonnage quantities
• Materials must be safe for incorporation into Laundry detergent products
• Materials that do not have required safety and regulatory package available

Looking for materials that can be readily incorporated into laundry liquid detergents (i.e. cannot go through a new material registration)

Looking for quick solutions - Market implementation within 2-3 years or less.

Materials must be available for a Laundry environment, i.e. have appropriate safety and regulatory package (and REACH registered or pre-registered).
Material must be chemically stable in Laundry compositions, which may contain detergent enzymes.
Materials must fit cost structure appropriate to a Laundry detergent.

Ready to use solutions

• Business Type: Consumer Goods
• Annual Revenue: Multi-billion USD
• Years in Business: 100
• Headquarters Location: Europe